pragma solidity =0.6.6;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}

contract UniswapV2Router02 is IUniswapV2Router02 {
    using SafeMath for uint;

    address public immutable override factory;
    address public immutable override WETH;

    modifier ensure(uint deadline) {
        require(deadline >= block.timestamp, 'UniswapV2Router: EXPIRED');
        _;
    }

    constructor(address _factory, address _WETH) public {
        factory = _factory;
        WETH = _WETH;
    }

    receive() external payable {
        assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract
    }

    // **** ADD LIQUIDITY ****
    function _addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin
    ) internal virtual returns (uint amountA, uint amountB) {
        // create the pair if it doesn't exist yet
        if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) {
            IUniswapV2Factory(factory).createPair(tokenA, tokenB);
        }
        (uint reserveA, uint reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB);
        if (reserveA == 0 && reserveB == 0) {
            (amountA, amountB) = (amountADesired, amountBDesired);
        } else {
            uint amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB);
            if (amountBOptimal <= amountBDesired) {
                require(amountBOptimal >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
                (amountA, amountB) = (amountADesired, amountBOptimal);
            } else {
                uint amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA);
                assert(amountAOptimal <= amountADesired);
                require(amountAOptimal >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
                (amountA, amountB) = (amountAOptimal, amountBDesired);
            }
        }
    }
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
        (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA);
        TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB);
        liquidity = IUniswapV2Pair(pair).mint(to);
    }
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
        (amountToken, amountETH) = _addLiquidity(
            token,
            WETH,
            amountTokenDesired,
            msg.value,
            amountTokenMin,
            amountETHMin
        );
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken);
        IWETH(WETH).deposit{value: amountETH}();
        assert(IWETH(WETH).transfer(pair, amountETH));
        liquidity = IUniswapV2Pair(pair).mint(to);
        // refund dust eth, if any
        if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
    }

    // **** REMOVE LIQUIDITY ****
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair
        (uint amount0, uint amount1) = IUniswapV2Pair(pair).burn(to);
        (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB);
        (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0);
        require(amountA >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
        require(amountB >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
    }
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
        (amountToken, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, amountToken);
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline);
    }
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountToken, uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline);
    }

    // **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) ****
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountETH) {
        (, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this)));
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        amountETH = removeLiquidityETHSupportingFeeOnTransferTokens(
            token, liquidity, amountTokenMin, amountETHMin, to, deadline
        );
    }

    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(uint[] memory amounts, address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            uint amountOut = amounts[i + 1];
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOut) : (amountOut, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap(
                amount0Out, amount1Out, to, new bytes(0)
            );
        }
    }
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
    }
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= msg.value, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
        // refund dust eth, if any
        if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]);
    }

    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output));
            uint amountInput;
            uint amountOutput;
            { // scope to avoid stack too deep errors
            (uint reserve0, uint reserve1,) = pair.getReserves();
            (uint reserveInput, uint reserveOutput) = input == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
            amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
            amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOutput) : (amountOutput, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) {
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        payable
        ensure(deadline)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        uint amountIn = msg.value;
        IWETH(WETH).deposit{value: amountIn}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn));
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        ensure(deadline)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        _swapSupportingFeeOnTransferTokens(path, address(this));
        uint amountOut = IERC20(WETH).balanceOf(address(this));
        require(amountOut >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).withdraw(amountOut);
        TransferHelper.safeTransferETH(to, amountOut);
    }

    // **** LIBRARY FUNCTIONS ****
    function quote(uint amountA, uint reserveA, uint reserveB) public pure virtual override returns (uint amountB) {
        return UniswapV2Library.quote(amountA, reserveA, reserveB);
    }

    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountOut)
    {
        return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
    }

    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountIn)
    {
        return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
    }

    function getAmountsOut(uint amountIn, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsOut(factory, amountIn, path);
    }

    function getAmountsIn(uint amountOut, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsIn(factory, amountOut, path);
    }
}

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

library UniswapV2Library {
    using SafeMath for uint;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(uint(keccak256(abi.encodePacked(
                hex'ff',
                factory,
                keccak256(abi.encodePacked(token0, token1)),
                hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f' // init code hash
            ))));
    }

    // fetches and sorts the reserves for a pair
    function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
        (address token0,) = sortTokens(tokenA, tokenB);
        (uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
        require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
        require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
        require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint amountInWithFee = amountIn.mul(997);
        uint numerator = amountInWithFee.mul(reserveOut);
        uint denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
        require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint numerator = reserveIn.mul(amountOut).mul(1000);
        uint denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[0] = amountIn;
        for (uint i; i < path.length - 1; i++) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint i = path.length - 1; i > 0; i--) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
    }

    function safeTransfer(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
    }

    function safeTransferFrom(address token, address from, address to, uint value) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
    }

    function safeTransferETH(address to, uint value) internal {
        (bool success,) = to.call{value:value}(new bytes(0));
        require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
    }
}

// Copyright (C) 2015, 2016, 2017 Dapphub

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
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            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

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    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<http://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

*/

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

{"Address.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts\n        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned\n        // for accounts without code, i.e. `keccak256(\u0027\u0027)`\n        bytes32 codehash;\n        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { codehash := extcodehash(account) }\n        return (codehash != accountHash \u0026\u0026 codehash != 0x0);\n    }\n\n    /**\n     * @dev Replacement for Solidity\u0027s `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance \u003e= amount, \"Address: insufficient balance\");\n\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\n        (bool success, ) = recipient.call{ value: amount }(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain`call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n      return functionCall(target, data, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\n        return _functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {\n        require(address(this).balance \u003e= value, \"Address: insufficient balance for call\");\n        return _functionCallWithValue(target, data, value, errorMessage);\n    }\n\n    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {\n        require(isContract(target), \"Address: call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);\n        if (success) {\n            return returndata;\n        } else {\n            // Look for revert reason and bubble it up if present\n            if (returndata.length \u003e 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\n                // solhint-disable-next-line no-inline-assembly\n                assembly {\n                    let returndata_size := mload(returndata)\n                    revert(add(32, returndata), returndata_size)\n                }\n            } else {\n                revert(errorMessage);\n            }\n        }\n    }\n}"},"Context.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/GSN/Context.sol\n\n/*\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with GSN meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address payable) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes memory) {\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n        return msg.data;\n    }\n}"},"ERC20.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./Context.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\n\n// File: @openzeppelin/contracts/token/ERC20/ERC20.sol\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * We have followed general OpenZeppelin guidelines: functions revert instead\n * of returning `false` on failure. This behavior is nonetheless conventional\n * and does not conflict with the expectations of ERC20 applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn\u0027t required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract ERC20 is Context, IERC20 {\n    using SafeMath for uint256;\n\n    mapping (address =\u003e uint256) internal _balances;\n\n    mapping (address =\u003e mapping (address =\u003e uint256)) private _allowances;\n\n    uint256 private _totalSupply;\n\n    string private _name;\n    string private _symbol;\n    uint8 private _decimals;\n\n    /**\n     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with\n     * a default value of 18.\n     *\n     * To select a different value for {decimals}, use {_setupDecimals}.\n     *\n     * All three of these values are immutable: they can only be set once during\n     * construction.\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n        _decimals = 18;\n    }\n\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() public view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Returns the symbol of the token, usually a shorter version of the\n     * name.\n     */\n    function symbol() public view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns the number of decimals used to get its user representation.\n     * For example, if `decimals` equals `2`, a balance of `505` tokens should\n     * be displayed to a user as `5,05` (`505 / 10 ** 2`).\n     *\n     * Tokens usually opt for a value of 18, imitating the relationship between\n     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is\n     * called.\n     *\n     * NOTE: This information is only used for _display_ purposes: it in\n     * no way affects any of the arithmetic of the contract, including\n     * {IERC20-balanceOf} and {IERC20-transfer}.\n     */\n    function decimals() public view override returns (uint8) {\n        return _decimals;\n    }\n\n    /**\n     * @dev See {IERC20-totalSupply}.\n     */\n    function totalSupply() public view override returns (uint256) {\n        return _totalSupply;\n    }\n\n    /**\n     * @dev See {IERC20-balanceOf}.\n     */\n    function balanceOf(address account) public view override returns (uint256) {\n        return _balances[account];\n    }\n\n    /**\n     * @dev See {IERC20-transfer}.\n     *\n     * Requirements:\n     *\n     * - `recipient` cannot be the zero address.\n     * - the caller must have a balance of at least `amount`.\n     */\n    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(_msgSender(), recipient, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-allowance}.\n     */\n    function allowance(address owner, address spender) public view virtual override returns (uint256) {\n        return _allowances[owner][spender];\n    }\n\n    /**\n     * @dev See {IERC20-approve}.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function approve(address spender, uint256 amount) public virtual override returns (bool) {\n        _approve(_msgSender(), spender, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-transferFrom}.\n     *\n     * Emits an {Approval} event indicating the updated allowance. This is not\n     * required by the EIP. See the note at the beginning of {ERC20};\n     *\n     * Requirements:\n     * - `sender` and `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     * - the caller must have allowance for ``sender``\u0027s tokens of at least\n     * `amount`.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(sender, recipient, amount);\n        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"ERC20: transfer amount exceeds allowance\"));\n        return true;\n    }\n\n    /**\n     * @dev Atomically increases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\n        return true;\n    }\n\n    /**\n     * @dev Atomically decreases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `spender` must have allowance for the caller of at least\n     * `subtractedValue`.\n     */\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"ERC20: decreased allowance below zero\"));\n        return true;\n    }\n\n    /**\n     * @dev Moves tokens `amount` from `sender` to `recipient`.\n     *\n     * This is internal function is equivalent to {transfer}, and can be used to\n     * e.g. implement automatic token fees, slashing mechanisms, etc.\n     *\n     * Emits a {Transfer} event.\n     *\n     * Requirements:\n     *\n     * - `sender` cannot be the zero address.\n     * - `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     */\n    function _transfer(address sender, address recipient, uint256 amount) internal virtual {\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        _beforeTokenTransfer(sender, recipient, amount);\n\n        _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n        _balances[recipient] = _balances[recipient].add(amount);\n        emit Transfer(sender, recipient, amount);\n    }\n\n    /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n     * the total supply.\n     *\n     * Emits a {Transfer} event with `from` set to the zero address.\n     *\n     * Requirements\n     *\n     * - `to` cannot be the zero address.\n     */\n    function _mint(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: mint to the zero address\");\n\n        _beforeTokenTransfer(address(0), account, amount);\n\n        _totalSupply = _totalSupply.add(amount);\n        _balances[account] = _balances[account].add(amount);\n        emit Transfer(address(0), account, amount);\n    }\n\n    /**\n     * @dev Destroys `amount` tokens from `account`, reducing the\n     * total supply.\n     *\n     * Emits a {Transfer} event with `to` set to the zero address.\n     *\n     * Requirements\n     *\n     * - `account` cannot be the zero address.\n     * - `account` must have at least `amount` tokens.\n     */\n    function _burn(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: burn from the zero address\");\n\n        _beforeTokenTransfer(account, address(0), amount);\n\n        _balances[account] = _balances[account].sub(amount, \"ERC20: burn amount exceeds balance\");\n        _totalSupply = _totalSupply.sub(amount);\n        emit Transfer(account, address(0), amount);\n    }\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.\n     *\n     * This is internal function is equivalent to `approve`, and can be used to\n     * e.g. set automatic allowances for certain subsystems, etc.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `owner` cannot be the zero address.\n     * - `spender` cannot be the zero address.\n     */\n    function _approve(address owner, address spender, uint256 amount) internal virtual {\n        require(owner != address(0), \"ERC20: approve from the zero address\");\n        require(spender != address(0), \"ERC20: approve to the zero address\");\n\n        _allowances[owner][spender] = amount;\n        emit Approval(owner, spender, amount);\n    }\n\n    /**\n     * @dev Sets {decimals} to a value other than the default one of 18.\n     *\n     * WARNING: This function should only be called from the constructor. Most\n     * applications that interact with token contracts will not expect\n     * {decimals} to ever change, and may work incorrectly if it does.\n     */\n    function _setupDecimals(uint8 decimals_) internal {\n        _decimals = decimals_;\n    }\n\n    /**\n     * @dev Hook that is called before any transfer of tokens. This includes\n     * minting and burning.\n     *\n     * Calling conditions:\n     *\n     * - when `from` and `to` are both non-zero, `amount` of ``from``\u0027s tokens\n     * will be to transferred to `to`.\n     * - when `from` is zero, `amount` tokens will be minted for `to`.\n     * - when `to` is zero, `amount` of ``from``\u0027s tokens will be burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }\n}"},"IERC20.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/token/ERC20/IERC20.sol\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Returns the number of decimal places.\n     */\n    function decimals() external view returns (uint8);\n\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller\u0027s account to `recipient`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n}"},"IUniswapV2Pair.sol":{"content":"\npragma solidity ^0.6.12;\n\ninterface IUniswapV2Pair {\n    event Approval(address indexed owner, address indexed spender, uint value);\n    event Transfer(address indexed from, address indexed to, uint value);\n\n    function name() external pure returns (string memory);\n    function symbol() external pure returns (string memory);\n    function decimals() external pure returns (uint8);\n    function totalSupply() external view returns (uint);\n    function balanceOf(address owner) external view returns (uint);\n    function allowance(address owner, address spender) external view returns (uint);\n\n    function approve(address spender, uint value) external returns (bool);\n    function transfer(address to, uint value) external returns (bool);\n    function transferFrom(address from, address to, uint value) external returns (bool);\n\n    function DOMAIN_SEPARATOR() external view returns (bytes32);\n    function PERMIT_TYPEHASH() external pure returns (bytes32);\n    function nonces(address owner) external view returns (uint);\n\n    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;\n\n    event Mint(address indexed sender, uint amount0, uint amount1);\n    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);\n    event Swap(\n        address indexed sender,\n        uint amount0In,\n        uint amount1In,\n        uint amount0Out,\n        uint amount1Out,\n        address indexed to\n    );\n    event Sync(uint112 reserve0, uint112 reserve1);\n\n    function MINIMUM_LIQUIDITY() external pure returns (uint);\n    function factory() external view returns (address);\n    function token0() external view returns (address);\n    function token1() external view returns (address);\n    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);\n    function price0CumulativeLast() external view returns (uint);\n    function price1CumulativeLast() external view returns (uint);\n    function kLast() external view returns (uint);\n\n    function mint(address to) external returns (uint liquidity);\n    function burn(address to) external returns (uint amount0, uint amount1);\n    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;\n    function skim(address to) external;\n    function sync() external;\n\n    function initialize(address, address) external;\n}"},"IUniswapV2Router02.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol\n\ninterface IUniswapV2Router01 {\n    function factory() external pure returns (address);\n    function WETH() external pure returns (address);\n\n    function addLiquidity(\n        address tokenA,\n        address tokenB,\n        uint amountADesired,\n        uint amountBDesired,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountA, uint amountB, uint liquidity);\n    function addLiquidityETH(\n        address token,\n        uint amountTokenDesired,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);\n    function removeLiquidity(\n        address tokenA,\n        address tokenB,\n        uint liquidity,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountA, uint amountB);\n    function removeLiquidityETH(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountToken, uint amountETH);\n    function removeLiquidityWithPermit(\n        address tokenA,\n        address tokenB,\n        uint liquidity,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountA, uint amountB);\n    function removeLiquidityETHWithPermit(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountToken, uint amountETH);\n    function swapExactTokensForTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external returns (uint[] memory amounts);\n    function swapTokensForExactTokens(\n        uint amountOut,\n        uint amountInMax,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external returns (uint[] memory amounts);\n    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)\n        external\n        payable\n        returns (uint[] memory amounts);\n    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)\n        external\n        returns (uint[] memory amounts);\n    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)\n        external\n        returns (uint[] memory amounts);\n    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)\n        external\n        payable\n        returns (uint[] memory amounts);\n\n    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);\n    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);\n    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);\n    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);\n    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);\n}\n\ninterface IUniswapV2Router02 is IUniswapV2Router01 {\n    function removeLiquidityETHSupportingFeeOnTransferTokens(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountETH);\n    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountETH);\n\n    function swapExactTokensForTokensSupportingFeeOnTransferTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external;\n    function swapExactETHForTokensSupportingFeeOnTransferTokens(\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external payable;\n    function swapExactTokensForETHSupportingFeeOnTransferTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external;\n}"},"Ownable.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./Context.sol\u0027;\n\n// File: @openzeppelin/contracts/access/Ownable.sol\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\ncontract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor () internal {\n        address msgSender = _msgSender();\n        _owner = msgSender;\n        emit OwnershipTransferred(address(0), msgSender);\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        require(_owner == _msgSender(), \"Ownable: caller is not the owner\");\n        _;\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        emit OwnershipTransferred(_owner, address(0));\n        _owner = address(0);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        emit OwnershipTransferred(_owner, newOwner);\n        _owner = newOwner;\n    }\n}"},"SafeERC20.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./Address.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\n\n// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n    using SafeMath for uint256;\n    using Address for address;\n\n    function safeTransfer(IERC20 token, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n    }\n\n    /**\n     * @dev Deprecated. This function has issues similar to the ones found in\n     * {IERC20-approve}, and its usage is discouraged.\n     *\n     * Whenever possible, use {safeIncreaseAllowance} and\n     * {safeDecreaseAllowance} instead.\n     */\n    function safeApprove(IERC20 token, address spender, uint256 value) internal {\n        // safeApprove should only be called when setting an initial allowance,\n        // or when resetting it to zero. To increase and decrease it, use\n        // \u0027safeIncreaseAllowance\u0027 and \u0027safeDecreaseAllowance\u0027\n        // solhint-disable-next-line max-line-length\n        require((value == 0) || (token.allowance(address(this), spender) == 0),\n            \"SafeERC20: approve from non-zero to non-zero allowance\"\n        );\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n    }\n\n    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).add(value);\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).sub(value, \"SafeERC20: decreased allowance below zero\");\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     */\n    function _callOptionalReturn(IERC20 token, bytes memory data) private {\n        // We need to perform a low level call here, to bypass Solidity\u0027s return data size checking mechanism, since\n        // we\u0027re implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that\n        // the target address contains contract code and also asserts for success in the low-level call.\n\n        bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n        if (returndata.length \u003e 0) { // Return data is optional\n            // solhint-disable-next-line max-line-length\n            require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n        }\n    }\n}"},"SafeMath.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\n/**\n * @dev Wrappers over Solidity\u0027s arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it\u0027s recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c \u003e= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        return sub(a, b, \"SafeMath: subtraction overflow\");\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003c= a, errorMessage);\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\n        // benefit is lost if \u0027b\u0027 is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        return div(a, b, \"SafeMath: division by zero\");\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003e 0, errorMessage);\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn\u0027t hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        return mod(a, b, \"SafeMath: modulo by zero\");\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts with custom message when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b != 0, errorMessage);\n        return a % b;\n    }\n}"},"SURF.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./ERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./Whirlpool.sol\u0027;\n\ninterface Callable {\n    function tokenCallback(address _from, uint256 _tokens, bytes calldata _data) external returns (bool);\n    function receiveApproval(address _from, uint256 _tokens, address _token, bytes calldata _data) external;\n}\n\n// SURF Token with Governance. The governance contract will own the SURF, Tito, and Whirlpool contracts,\n// allowing SURF token holders to make and vote on proposals that can modify many parts of the protocol.\ncontract SURF is ERC20(\"SURF.Finance\", \"SURF\"), Ownable {\n\n    // There will be a max supply of 10,000,000 SURF tokens\n    uint256 public constant MAX_SUPPLY = 10000000 * 10**18;\n    bool public maxSupplyHit = false;\n\n    // The SURF transfer fee that gets rewarded to Whirlpool stakers (1 = 0.1%). Defaults to 1%\n    uint256 public transferFee = 10;\n\n    // Mapping of whitelisted sender and recipient addresses that don\u0027t pay the transfer fee. Allows SURF token holders to whitelist future contracts\n    mapping(address =\u003e bool) public senderWhitelist;\n    mapping(address =\u003e bool) public recipientWhitelist;\n\n    // The Tito contract\n    address public titoAddress;\n\n    // The Whirlpool contract\n    address payable public whirlpoolAddress;\n\n    // The Uniswap SURF-ETH LP token address\n    address public surfPoolAddress;\n\n    // Creates `_amount` token to `_to`. Can only be called by the Tito contract.\n    function mint(address _to, uint256 _amount) public {\n        require(maxSupplyHit != true, \"max supply hit\");\n        require(msg.sender == titoAddress, \"not Tito\");\n        uint256 supply = totalSupply();\n        if (supply.add(_amount) \u003e= MAX_SUPPLY) {\n            _amount = MAX_SUPPLY.sub(supply);\n            maxSupplyHit = true;\n        }\n\n        if (_amount \u003e 0) {\n            _mint(_to, _amount);\n            _moveDelegates(address(0), _delegates[_to], _amount);\n        }\n    }\n\n    // Sets the addresses of the Tito farming contract, the Whirlpool staking contract, and the Uniswap SURF-ETH LP token\n    function setContractAddresses(address _titoAddress, address payable _whirlpoolAddress, address _surfPoolAddress) public onlyOwner {\n        if (_titoAddress != address(0)) titoAddress = _titoAddress;\n        if (_whirlpoolAddress != address(0)) whirlpoolAddress = _whirlpoolAddress;\n        if (_surfPoolAddress != address(0)) surfPoolAddress = _surfPoolAddress;\n    }\n\n    // Sets the SURF transfer fee that gets rewarded to Whirlpool stakers. Can\u0027t be higher than 10%.\n    function setTransferFee(uint256 _transferFee) public onlyOwner {\n        require(_transferFee \u003c= 100, \"over 10%\");\n        transferFee = _transferFee;\n    }\n\n    // Add an address to the sender or recipient transfer whitelist\n    function addToTransferWhitelist(bool _addToSenderWhitelist, address _address) public onlyOwner {\n        if (_addToSenderWhitelist == true) senderWhitelist[_address] = true;\n        else recipientWhitelist[_address] = true;\n    }\n\n    // Remove an address from the sender or recipient transfer whitelist\n    function removeFromTransferWhitelist(bool _removeFromSenderWhitelist, address _address) public onlyOwner {\n        if (_removeFromSenderWhitelist == true) senderWhitelist[_address] = false;\n        else recipientWhitelist[_address] = false;\n    }\n\n    // Both the Tito and Whirlpool contracts will lock the SURF-ETH LP tokens they receive from their staking/unstaking fees here (ensuring liquidity forever).\n    // This function allows SURF token holders to decide what to do with the locked LP tokens in the future\n    function migrateLockedLPTokens(address _to, uint256 _amount) public onlyOwner {\n        IERC20 surfPool = IERC20(surfPoolAddress);\n        require(_amount \u003e 0 \u0026\u0026 _amount \u003c= surfPool.balanceOf(address(this)), \"bad amount\");\n        surfPool.transfer(_to, _amount);\n    }\n\n    function approveAndCall(address _spender, uint256 _tokens, bytes calldata _data) external returns (bool) {\n        approve(_spender, _tokens);\n        Callable(_spender).receiveApproval(msg.sender, _tokens, address(this), _data);\n        return true;\n    }\n\n    function transferAndCall(address _to, uint256 _tokens, bytes calldata _data) external returns (bool) {\n        uint256 _balanceBefore = balanceOf(_to);\n        transfer(_to, _tokens);\n        uint256 _tokensReceived = balanceOf(_to) - _balanceBefore;\n        uint32 _size;\n        assembly {\n            _size := extcodesize(_to)\n        }\n        if (_size \u003e 0) {\n            require(Callable(_to).tokenCallback(msg.sender, _tokensReceived, _data));\n        }\n        return true;\n    }\n\n    // There\u0027s a fee on every SURF transfer that gets sent to the Whirlpool staking contract which will start getting rewarded to stakers after the max supply is hit.\n    // The transfer fee will reduce the front-running of Uniswap trades and will provide a major incentive to hold and stake SURF long-term.\n    // Transfers to/from the Tito or Whirlpool contracts will not pay a fee.\n    function _transfer(address sender, address recipient, uint256 amount) internal override {\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        uint256 transferFeeAmount;\n        uint256 tokensToTransfer;\n\n        if (amount \u003e 0) {\n\n            // Send a fee to the Whirlpool staking contract if this isn\u0027t a whitelisted transfer\n            if (_isWhitelistedTransfer(sender, recipient) != true) {\n                transferFeeAmount = amount.mul(transferFee).div(1000);\n                _balances[whirlpoolAddress] = _balances[whirlpoolAddress].add(transferFeeAmount);\n                _moveDelegates(_delegates[sender], _delegates[whirlpoolAddress], transferFeeAmount);\n                Whirlpool(whirlpoolAddress).addSurfReward(sender, transferFeeAmount);\n                emit Transfer(sender, whirlpoolAddress, transferFeeAmount);\n            }\n\n            tokensToTransfer = amount.sub(transferFeeAmount);\n\n            _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n\n            if (tokensToTransfer \u003e 0) {\n                _balances[recipient] = _balances[recipient].add(tokensToTransfer);\n                _moveDelegates(_delegates[sender], _delegates[recipient], tokensToTransfer);\n\n                // If the Whirlpool staking contract is the transfer recipient, addSurfReward gets called to keep things in sync\n                if (recipient == whirlpoolAddress) Whirlpool(whirlpoolAddress).addSurfReward(sender, tokensToTransfer);\n            }\n\n        }\n\n        emit Transfer(sender, recipient, tokensToTransfer);\n    }\n\n    // Internal function to determine if a SURF transfer is being sent or received by a whitelisted address\n    function _isWhitelistedTransfer(address _sender, address _recipient) internal view returns (bool) {\n        // The Whirlpool and Tito contracts are always whitelisted\n        return\n            _sender == whirlpoolAddress || _recipient == whirlpoolAddress ||\n            _sender == titoAddress || _recipient == titoAddress ||\n            senderWhitelist[_sender] == true || recipientWhitelist[_recipient] == true;\n    }\n\n    // Copied and modified from YAM code:\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol\n    // Which is copied and modified from COMPOUND:\n    // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol\n\n    /// @dev A record of each accounts delegate\n    mapping (address =\u003e address) internal _delegates;\n\n    /// @dev A checkpoint for marking number of votes from a given block\n    struct Checkpoint {\n        uint32 fromBlock;\n        uint256 votes;\n    }\n\n    /// @dev A record of votes checkpoints for each account, by index\n    mapping (address =\u003e mapping (uint32 =\u003e Checkpoint)) public checkpoints;\n\n    /// @dev The number of checkpoints for each account\n    mapping (address =\u003e uint32) public numCheckpoints;\n\n    /// @dev The EIP-712 typehash for the contract\u0027s domain\n    bytes32 public constant DOMAIN_TYPEHASH = keccak256(\"EIP712Domain(string name,uint256 chainId,address verifyingContract)\");\n\n    /// @dev The EIP-712 typehash for the delegation struct used by the contract\n    bytes32 public constant DELEGATION_TYPEHASH = keccak256(\"Delegation(address delegatee,uint256 nonce,uint256 expiry)\");\n\n    /// @dev A record of states for signing / validating signatures\n    mapping (address =\u003e uint) public nonces;\n\n      /// @dev An event thats emitted when an account changes its delegate\n    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);\n\n    /// @dev An event thats emitted when a delegate account\u0027s vote balance changes\n    event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);\n\n    /**\n     * @dev Delegate votes from `msg.sender` to `delegatee`\n     * @param delegator The address to get delegatee for\n     */\n    function delegates(address delegator) external view returns (address) {\n        return _delegates[delegator];\n    }\n\n   /**\n    * @dev Delegate votes from `msg.sender` to `delegatee`\n    * @param delegatee The address to delegate votes to\n    */\n    function delegate(address delegatee) external {\n        return _delegate(msg.sender, delegatee);\n    }\n\n    /**\n     * @dev Delegates votes from signatory to `delegatee`\n     * @param delegatee The address to delegate votes to\n     * @param nonce The contract state required to match the signature\n     * @param expiry The time at which to expire the signature\n     * @param v The recovery byte of the signature\n     * @param r Half of the ECDSA signature pair\n     * @param s Half of the ECDSA signature pair\n     */\n    function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) external {\n        bytes32 domainSeparator = keccak256(\n            abi.encode(\n                DOMAIN_TYPEHASH,\n                keccak256(bytes(name())),\n                getChainId(),\n                address(this)\n            )\n        );\n\n        bytes32 structHash = keccak256(\n            abi.encode(\n                DELEGATION_TYPEHASH,\n                delegatee,\n                nonce,\n                expiry\n            )\n        );\n\n        bytes32 digest = keccak256(\n            abi.encodePacked(\n                \"\\x19\\x01\",\n                domainSeparator,\n                structHash\n            )\n        );\n\n        address signatory = ecrecover(digest, v, r, s);\n        require(signatory != address(0), \"SURF::delegateBySig: invalid signature\");\n        require(nonce == nonces[signatory]++, \"SURF::delegateBySig: invalid nonce\");\n        require(now \u003c= expiry, \"SURF::delegateBySig: signature expired\");\n        return _delegate(signatory, delegatee);\n    }\n\n    /**\n     * @dev Gets the current votes balance for `account`\n     * @param account The address to get votes balance\n     * @return The number of current votes for `account`\n     */\n    function getCurrentVotes(address account) external view returns (uint256) {\n        uint32 nCheckpoints = numCheckpoints[account];\n        return nCheckpoints \u003e 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;\n    }\n\n    /**\n     * @dev Determine the prior number of votes for an account as of a block number\n     * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.\n     * @param account The address of the account to check\n     * @param blockNumber The block number to get the vote balance at\n     * @return The number of votes the account had as of the given block\n     */\n    function getPriorVotes(address account, uint blockNumber) external view returns (uint256) {\n        require(blockNumber \u003c block.number, \"SURF::getPriorVotes: not yet determined\");\n\n        uint32 nCheckpoints = numCheckpoints[account];\n        if (nCheckpoints == 0) {\n            return 0;\n        }\n\n        // First check most recent balance\n        if (checkpoints[account][nCheckpoints - 1].fromBlock \u003c= blockNumber) {\n            return checkpoints[account][nCheckpoints - 1].votes;\n        }\n\n        // Next check implicit zero balance\n        if (checkpoints[account][0].fromBlock \u003e blockNumber) {\n            return 0;\n        }\n\n        uint32 lower = 0;\n        uint32 upper = nCheckpoints - 1;\n        while (upper \u003e lower) {\n            uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow\n            Checkpoint memory cp = checkpoints[account][center];\n            if (cp.fromBlock == blockNumber) {\n                return cp.votes;\n            } else if (cp.fromBlock \u003c blockNumber) {\n                lower = center;\n            } else {\n                upper = center - 1;\n            }\n        }\n        return checkpoints[account][lower].votes;\n    }\n\n    function _delegate(address delegator, address delegatee) internal {\n        address currentDelegate = _delegates[delegator];\n        uint256 delegatorBalance = balanceOf(delegator); // balance of underlying SURFs (not scaled);\n        _delegates[delegator] = delegatee;\n\n        emit DelegateChanged(delegator, currentDelegate, delegatee);\n\n        _moveDelegates(currentDelegate, delegatee, delegatorBalance);\n    }\n\n    function _moveDelegates(address srcRep, address dstRep, uint256 amount) internal {\n        if (srcRep != dstRep \u0026\u0026 amount \u003e 0) {\n            if (srcRep != address(0)) {\n                // decrease old representative\n                uint32 srcRepNum = numCheckpoints[srcRep];\n                uint256 srcRepOld = srcRepNum \u003e 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;\n                uint256 srcRepNew = srcRepOld.sub(amount);\n                _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);\n            }\n\n            if (dstRep != address(0)) {\n                // increase new representative\n                uint32 dstRepNum = numCheckpoints[dstRep];\n                uint256 dstRepOld = dstRepNum \u003e 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;\n                uint256 dstRepNew = dstRepOld.add(amount);\n                _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);\n            }\n        }\n    }\n\n    function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint256 oldVotes, uint256 newVotes) internal {\n        uint32 blockNumber = safe32(block.number, \"SURF::_writeCheckpoint: block number exceeds 32 bits\");\n\n        if (nCheckpoints \u003e 0 \u0026\u0026 checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {\n            checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;\n        } else {\n            checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);\n            numCheckpoints[delegatee] = nCheckpoints + 1;\n        }\n\n        emit DelegateVotesChanged(delegatee, oldVotes, newVotes);\n    }\n\n    function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {\n        require(n \u003c 2**32, errorMessage);\n        return uint32(n);\n    }\n\n    function getChainId() internal pure returns (uint) {\n        uint256 chainId;\n        assembly { chainId := chainid() }\n        return chainId;\n    }\n}"},"Tito.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./SafeERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./IUniswapV2Router02.sol\u0027;\nimport \u0027./UniStakingInterfaces.sol\u0027;\nimport \u0027./SURF.sol\u0027;\nimport \u0027./Whirlpool.sol\u0027;\n\n// Tito is the master of SURF. He can make SURF, is a fair guy, and a great instructor.\ncontract Tito is Ownable {\n    using SafeMath for uint256;\n    using SafeERC20 for IERC20;\n\n    // Info of each user.\n    struct UserInfo {\n        uint256 staked; // How many LP tokens the user has provided.\n        uint256 rewardDebt; // Reward debt. See explanation below.\n        uint256 uniRewardDebt; // UNI staking reward debt. See explanation below.\n        uint256 claimed; // Tracks the amount of SURF claimed by the user.\n        uint256 uniClaimed; // Tracks the amount of UNI claimed by the user.\n    }\n\n    // Info of each pool.\n    struct PoolInfo {\n        IERC20 token; // Address of token contract.\n        IERC20 lpToken; // Address of LP token contract.\n        uint256 apr; // Fixed APR for the pool. Determines how many SURFs to distribute per block.\n        uint256 lastSurfRewardBlock; // Last block number that SURF rewards were distributed.\n        uint256 accSurfPerShare; // Accumulated SURFs per share, times 1e12. See below.\n        uint256 accUniPerShare; // Accumulated UNIs per share, times 1e12. See below.\n        address uniStakeContract; // Address of UNI staking contract (if applicable).\n    }\n\n    // We do some fancy math here. Basically, any point in time, the amount of SURFs\n    // entitled to a user but is pending to be distributed is:\n    //\n    //   pending reward = (user.staked * pool.accSurfPerShare) - user.rewardDebt\n    //\n    // Whenever a user deposits or withdraws LP tokens to a pool. Here\u0027s what happens:\n    //   1. The pool\u0027s `accSurfPerShare` (and `lastSurfRewardBlock`) gets updated.\n    //   2. User receives the pending reward sent to his/her address.\n    //   3. User\u0027s `staked` amount gets updated.\n    //   4. User\u0027s `rewardDebt` gets updated.\n\n    // The SURF TOKEN!\n    SURF public surf;\n    // The address of the SURF-ETH Uniswap pool\n    address public surfPoolAddress;\n     // The Whirlpool staking contract\n    Whirlpool public whirlpool;\n    // The Uniswap v2 Router\n    IUniswapV2Router02 internal uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);\n    // The UNI Staking Rewards Factory\n    StakingRewardsFactory internal uniStakingFactory = StakingRewardsFactory(0x3032Ab3Fa8C01d786D29dAdE018d7f2017918e12);\n    // The UNI Token\n    IERC20 internal uniToken = IERC20(0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984);\n    // The WETH Token\n    IERC20 internal weth;\n    // Dev address\n    address payable public devAddress;\n\n    // Info of each pool.\n    PoolInfo[] public poolInfo;\n    mapping(address =\u003e bool) public existingPools;\n    // Info of each user that stakes LP tokens.\n    mapping (uint256 =\u003e mapping (address =\u003e UserInfo)) public userInfo;\n    // Mapping of whitelisted contracts so that certain contracts like the Aegis pool can interact with the Tito contract\n    mapping(address =\u003e bool) public contractWhitelist;\n    // The block number when SURF mining starts.\n    uint256 public startBlock;\n    // Becomes true once the SURF-ETH Uniswap is created (no sooner than 500 blocks after launch)\n    bool public surfPoolActive = false;\n    // The staking fees collected during the first 500 blocks will seed the SURF-ETH Uniswap pool\n    uint256 public initialSurfPoolETH  = 0;\n    // 5% of every deposit into any secondary pool (not SURF-ETH) will be converted to SURF (on Uniswap) and sent to the Whirlpool staking contract which becomes active and starts distributing the accumulated SURF to stakers once the max supply is hit\n    uint256 public surfSentToWhirlpool = 0;\n    // The amount of ETH donated to the SURF community by partner projects\n    uint256 public donatedETH = 0;\n    // Certain partner projects need to donate 25 ETH to the SURF community to get a beach\n    uint256 internal constant minimumDonationAmount = 25 * 10**18;\n    // Mapping of addresses that donated ETH on behalf of a partner project\n    mapping(address =\u003e address) internal donaters;\n    // Mapping of the size of donations from partner projects\n    mapping(address =\u003e uint256) internal donations;\n    // Approximate number of blocks per year - assumes 13 second blocks\n    uint256 internal constant APPROX_BLOCKS_PER_YEAR  = uint256(uint256(365 days) / uint256(13 seconds));\n    // The default APR for each pool will be 1,000%\n    uint256 internal constant DEFAULT_APR = 1000;\n    // There will be a 1000 block Soft Launch in which SURF is minted to each pool at a static rate to make the start as fair as possible\n    uint256 internal constant SOFT_LAUNCH_DURATION = 1000;\n    // During the Soft Launch, all pools except for the SURF-ETH pool will mint 40 SURF per block. Once it\u0027s activated, the SURF-ETH pool will mint the same amount of SURF per block as all of the other pools combined until the end of the Soft Launch\n    uint256 internal constant SOFT_LAUNCH_SURF_PER_BLOCK = 40 * 10**18;\n\n    event Deposit(address indexed user, uint256 indexed pid, uint256 amount);\n    event Claim(address indexed user, uint256 indexed pid, uint256 surfAmount, uint256 uniAmount);\n    event ClaimAll(address indexed user, uint256 surfAmount, uint256 uniAmount);\n    event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);\n    event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);\n    event SurfBuyback(address indexed user, uint256 ethSpentOnSurf, uint256 surfBought);\n    event SurfPoolActive(address indexed user, uint256 surfLiquidity, uint256 ethLiquidity);\n\n    constructor(\n        SURF _surf,\n        address payable _devAddress,\n        uint256 _startBlock\n    ) public {\n        surf = _surf;\n        devAddress = _devAddress;\n        startBlock = _startBlock;\n        weth = IERC20(uniswapRouter.WETH());\n\n        // Calculate the address the SURF-ETH Uniswap pool will exist at\n        address uniswapfactoryAddress = uniswapRouter.factory();\n        address surfAddress = address(surf);\n        address wethAddress = address(weth);\n\n        // token0 must be strictly less than token1 by sort order to determine the correct address\n        (address token0, address token1) = surfAddress \u003c wethAddress ? (surfAddress, wethAddress) : (wethAddress, surfAddress);\n\n        surfPoolAddress = address(uint(keccak256(abi.encodePacked(\n            hex\u0027ff\u0027,\n            uniswapfactoryAddress,\n            keccak256(abi.encodePacked(token0, token1)),\n            hex\u002796e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f\u0027\n        ))));\n\n        _addInitialPools();\n    }\n\n    receive() external payable {}\n\n    // Internal function to add a new LP Token pool\n    function _addPool(address _token, address _lpToken) internal {\n\n        uint256 apr = DEFAULT_APR;\n        if (_token == address(surf)) apr = apr * 5;\n\n        uint256 lastSurfRewardBlock = block.number \u003e startBlock ? block.number : startBlock;\n\n        poolInfo.push(\n            PoolInfo({\n                token: IERC20(_token),\n                lpToken: IERC20(_lpToken),\n                apr: apr,\n                lastSurfRewardBlock: lastSurfRewardBlock,\n                accSurfPerShare: 0,\n                accUniPerShare: 0,\n                uniStakeContract: address(0)\n            })\n        );\n\n        existingPools[_lpToken] = true;\n    }\n\n    // Internal function that adds all of the pools that will be available at launch. Called by the constructor\n    function _addInitialPools() internal {\n\n        _addPool(address(surf), surfPoolAddress); // SURF-ETH\n\n        _addPool(0xdAC17F958D2ee523a2206206994597C13D831ec7, 0x0d4a11d5EEaaC28EC3F61d100daF4d40471f1852); // ETH-USDT\n        _addPool(0x6B175474E89094C44Da98b954EedeAC495271d0F, 0xA478c2975Ab1Ea89e8196811F51A7B7Ade33eB11); // DAI-ETH\n        _addPool(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, 0xB4e16d0168e52d35CaCD2c6185b44281Ec28C9Dc); // USDC-ETH\n        _addPool(0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599, 0xBb2b8038a1640196FbE3e38816F3e67Cba72D940); // WBTC-ETH\n        _addPool(0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, 0xd3d2E2692501A5c9Ca623199D38826e513033a17); // UNI-ETH\n        _addPool(0x514910771AF9Ca656af840dff83E8264EcF986CA, 0xa2107FA5B38d9bbd2C461D6EDf11B11A50F6b974); // LINK-ETH\n        _addPool(0x7Fc66500c84A76Ad7e9c93437bFc5Ac33E2DDaE9, 0xDFC14d2Af169B0D36C4EFF567Ada9b2E0CAE044f); // AAVE-ETH\n        _addPool(0xC011a73ee8576Fb46F5E1c5751cA3B9Fe0af2a6F, 0x43AE24960e5534731Fc831386c07755A2dc33D47); // SNX-ETH\n        _addPool(0x9f8F72aA9304c8B593d555F12eF6589cC3A579A2, 0xC2aDdA861F89bBB333c90c492cB837741916A225); // MKR-ETH\n        _addPool(0xc00e94Cb662C3520282E6f5717214004A7f26888, 0xCFfDdeD873554F362Ac02f8Fb1f02E5ada10516f); // COMP-ETH\n        _addPool(0x0bc529c00C6401aEF6D220BE8C6Ea1667F6Ad93e, 0x2fDbAdf3C4D5A8666Bc06645B8358ab803996E28); // YFI-ETH\n        _addPool(0xba100000625a3754423978a60c9317c58a424e3D, 0xA70d458A4d9Bc0e6571565faee18a48dA5c0D593); // BAL-ETH\n        _addPool(0x1494CA1F11D487c2bBe4543E90080AeBa4BA3C2b, 0x4d5ef58aAc27d99935E5b6B4A6778ff292059991); // DPI-ETH\n        _addPool(0xD46bA6D942050d489DBd938a2C909A5d5039A161, 0xc5be99A02C6857f9Eac67BbCE58DF5572498F40c); // AMPL-ETH\n        _addPool(0x2b591e99afE9f32eAA6214f7B7629768c40Eeb39, 0x55D5c232D921B9eAA6b37b5845E439aCD04b4DBa); // HEX-ETH\n        _addPool(0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d, 0x343FD171caf4F0287aE6b87D75A8964Dc44516Ab); // PNK-ETH\n        _addPool(0x429881672B9AE42b8EbA0E26cD9C73711b891Ca5, 0xdc98556Ce24f007A5eF6dC1CE96322d65832A819); // PICKLE-ETH\n        _addPool(0x84294FC9710e1252d407d3D80A84bC39001bd4A8, 0x0C5136B5d184379fa15bcA330784f2d5c226Fe96); // NUTS-ETH\n        _addPool(0x821144518dfE9e7b44fCF4d0824e15e8390d4637, 0x490B5B2489eeFC4106C69743F657e3c4A2870aC5); // ATIS-ETH\n        _addPool(0xB9464ef80880c5aeA54C7324c0b8Dd6ca6d05A90, 0xa8D0f6769AB020877f262D8Cd747c188D9097d7E); // LOCK-ETH\n        _addPool(0x926dbD499d701C61eABe2d576e770ECCF9c7F4F3, 0xC7c0EDf0b5f89eff96aF0E31643Bd588ad63Ea23); // aDAO-ETH\n        _addPool(0x3A9FfF453d50D4Ac52A6890647b823379ba36B9E, 0x260E069deAd76baAC587B5141bB606Ef8b9Bab6c); // SHUF-ETH\n        _addPool(0x9720Bcf5a92542D4e286792fc978B63a09731CF0, 0x08538213596fB2c392e9c5d4935ad37645600a57); // OTBC-ETH\n        _addPool(0xEEF9f339514298C6A857EfCfC1A762aF84438dEE, 0x23d15EDceb5B5B3A23347Fa425846DE80a2E8e5C); // HEZ-ETH\n\n        // These beaches will be manually added after their teams make the 25 ETH donation\n        // _addPool(0x6F87D756DAf0503d08Eb8993686c7Fc01Dc44fB1, 0xd2E0C4928789e5DB620e53af29F5fC7bcA262635); // TRADE-ETH\n        \n    }\n\n    // Get the pending SURFs for a user from 1 pool\n    function _pendingSurf(uint256 _pid, address _user) internal view returns (uint256) {\n        if (_pid == 0 \u0026\u0026 surfPoolActive != true) return 0;\n\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo memory user = userInfo[_pid][_user];\n        uint256 accSurfPerShare = pool.accSurfPerShare;\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        if (block.number \u003e pool.lastSurfRewardBlock \u0026\u0026 lpSupply != 0) {\n            uint256 surfReward = _calculateSurfReward(_pid, lpSupply);\n\n            // Make sure that surfReward won\u0027t push the total supply of SURF past surf.MAX_SUPPLY()\n            uint256 surfTotalSupply = surf.totalSupply();\n            if (surfTotalSupply.add(surfReward) \u003e= surf.MAX_SUPPLY()) {\n                surfReward = surf.MAX_SUPPLY().sub(surfTotalSupply);\n            }\n\n            accSurfPerShare = accSurfPerShare.add(surfReward.mul(1e12).div(lpSupply));\n        }\n\n        return user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n    }\n\n    // Get the pending UNIs for a user from 1 pool\n    function _pendingUni(uint256 _pid, address _user) internal view returns (uint256) {\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo memory user = userInfo[_pid][_user];\n        uint256 accUniPerShare = pool.accUniPerShare;\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        if (pool.uniStakeContract != address(0) \u0026\u0026 lpSupply != 0) {\n            uint256 uniReward = IStakingRewards(pool.uniStakeContract).earned(address(this));\n            accUniPerShare = accUniPerShare.add(uniReward.mul(1e12).div(lpSupply));\n        }\n        return user.staked.mul(accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n    }\n\n    // Calculate the current surfReward for a specific pool\n    function _calculateSurfReward(uint256 _pid, uint256 _lpSupply) internal view returns (uint256 surfReward) {\n        \n        if (surf.maxSupplyHit() != true) {\n\n            PoolInfo memory pool = poolInfo[_pid];\n\n            uint256 multiplier = block.number - pool.lastSurfRewardBlock;\n                \n            // There will be a 1000 block Soft Launch where SURF is minted at a static rate to make things as fair as possible\n            if (block.number \u003c startBlock + SOFT_LAUNCH_DURATION) {\n\n                // The SURF-ETH pool isn\u0027t active until the Uniswap pool is created, which can\u0027t happen until at least 500 blocks have passed. Once active, it mints 1000 SURF per block (the same amount of SURF per block as all of the other pools combined) until the Soft Launch ends\n                if (_pid != 0) {\n                    // For the first 1000 blocks, give 40 SURF per block to all other pools that have staked LP tokens\n                    surfReward = multiplier * SOFT_LAUNCH_SURF_PER_BLOCK;\n                } else if (surfPoolActive == true) {\n                    surfReward = multiplier * 25 * SOFT_LAUNCH_SURF_PER_BLOCK;\n                }\n            \n            } else if (_pid != 0 \u0026\u0026 surfPoolActive != true) {\n                // Keep minting 40 tokens per block since the Soft Launch is over but the SURF-ETH pool still isn\u0027t active (would only be due to no one calling the activateSurfPool function)\n                surfReward = multiplier * SOFT_LAUNCH_SURF_PER_BLOCK;\n            } else if (surfPoolActive == true) { \n                // Afterwards, give surfReward based on the pool\u0027s fixed APR.\n                // Fast low gas cost way of calculating prices since this can be called every block.\n                uint256 surfPrice = _getSurfPrice();\n                uint256 lpTokenPrice = 10**18 * 2 * weth.balanceOf(address(pool.lpToken)) / pool.lpToken.totalSupply(); \n                uint256 scaledTotalLiquidityValue = _lpSupply * lpTokenPrice;\n                surfReward = multiplier * ((pool.apr * scaledTotalLiquidityValue / surfPrice) / APPROX_BLOCKS_PER_YEAR) / 100;\n            }\n\n        }\n\n    }\n\n    function poolLength() external view returns (uint256) {\n        return poolInfo.length;\n    }\n\n    // Internal view function to get all of the stored data for a single pool\n    function _getPoolData(uint256 _pid) internal view returns (address, address, bool, uint256, uint256, uint256, uint256) {\n        PoolInfo memory pool = poolInfo[_pid];\n        return (address(pool.token), address(pool.lpToken), pool.uniStakeContract != address(0), pool.apr, pool.lastSurfRewardBlock, pool.accSurfPerShare, pool.accUniPerShare);\n    }\n\n    // View function to see all of the stored data for every pool on the frontend\n    function _getAllPoolData() internal view returns (address[] memory, address[] memory, bool[] memory, uint[] memory, uint[] memory, uint[2][] memory) {\n        uint256 length = poolInfo.length;\n        address[] memory tokenData = new address[](length);\n        address[] memory lpTokenData = new address[](length);\n        bool[] memory isUniData = new bool[](length);\n        uint[] memory aprData = new uint[](length);\n        uint[] memory lastSurfRewardBlockData = new uint[](length);\n        uint[2][] memory accTokensPerShareData = new uint[2][](length);\n\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            (tokenData[pid], lpTokenData[pid], isUniData[pid], aprData[pid], lastSurfRewardBlockData[pid], accTokensPerShareData[pid][0], accTokensPerShareData[pid][1]) = _getPoolData(pid);\n        }\n\n        return (tokenData, lpTokenData, isUniData, aprData, lastSurfRewardBlockData, accTokensPerShareData);\n    }\n\n    // Internal view function to get all of the extra data for a single pool\n    function _getPoolMetadataFor(uint256 _pid, address _user, uint256 _surfPrice) internal view returns (uint[17] memory poolMetadata) {\n        PoolInfo memory pool = poolInfo[_pid];\n\n        uint256 totalSupply;\n        uint256 totalLPSupply;\n        uint256 stakedLPSupply;\n        uint256 tokenPrice;\n        uint256 lpTokenPrice;\n        uint256 totalLiquidityValue;\n        uint256 surfPerBlock;\n\n        if (_pid != 0 || surfPoolActive == true) {\n            totalSupply = pool.token.totalSupply();\n            totalLPSupply = pool.lpToken.totalSupply();\n            stakedLPSupply = _getPoolSupply(_pid);\n\n            tokenPrice = 10**uint256(pool.token.decimals()) * weth.balanceOf(address(pool.lpToken)) / pool.token.balanceOf(address(pool.lpToken));\n            lpTokenPrice = 10**18 * 2 * weth.balanceOf(address(pool.lpToken)) / totalLPSupply; \n            totalLiquidityValue = stakedLPSupply * lpTokenPrice / 1e18;\n        }\n\n        // Only calculate with fixed apr after the Soft Launch\n        if (block.number \u003e= startBlock + SOFT_LAUNCH_DURATION) {\n            surfPerBlock = ((pool.apr * 1e18 * totalLiquidityValue / _surfPrice) / APPROX_BLOCKS_PER_YEAR) / 100;\n        } else {\n            if (_pid != 0) {\n                surfPerBlock = SOFT_LAUNCH_SURF_PER_BLOCK;\n            } else if (surfPoolActive == true) {\n                surfPerBlock = 25 * SOFT_LAUNCH_SURF_PER_BLOCK;\n            }\n        }\n\n        // Global pool information\n        poolMetadata[0] = totalSupply;\n        poolMetadata[1] = totalLPSupply;\n        poolMetadata[2] = stakedLPSupply;\n        poolMetadata[3] = tokenPrice;\n        poolMetadata[4] = lpTokenPrice;\n        poolMetadata[5] = totalLiquidityValue;\n        poolMetadata[6] = surfPerBlock;\n        poolMetadata[7] = pool.token.decimals();\n\n        // User pool information\n        if (_pid != 0 || surfPoolActive == true) {\n            UserInfo memory _userInfo = userInfo[_pid][_user];\n            poolMetadata[8] = pool.token.balanceOf(_user);\n            poolMetadata[9] = pool.token.allowance(_user, address(this));\n            poolMetadata[10] = pool.lpToken.balanceOf(_user);\n            poolMetadata[11] = pool.lpToken.allowance(_user, address(this));\n            poolMetadata[12] = _userInfo.staked;\n            poolMetadata[13] = _pendingSurf(_pid, _user);\n            poolMetadata[14] = _pendingUni(_pid, _user);\n            poolMetadata[15] = _userInfo.claimed;\n            poolMetadata[16] = _userInfo.uniClaimed;\n        }\n    }\n\n    // View function to see all of the extra pool data (token prices, total staked supply, total liquidity value, etc) on the frontend\n    function _getAllPoolMetadataFor(address _user) internal view returns (uint[17][] memory allMetadata) {\n        uint256 length = poolInfo.length;\n\n        // Extra data for the frontend\n        allMetadata = new uint[17][](length);\n\n        // We\u0027ll need the current SURF price to make our calculations\n        uint256 surfPrice = _getSurfPrice();\n\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            allMetadata[pid] = _getPoolMetadataFor(pid, _user, surfPrice);\n        }\n    }\n\n    // View function to see all of the data for all pools on the frontend\n    function getAllPoolInfoFor(address _user) external view returns (address[] memory tokens, address[] memory lpTokens, bool[] memory isUnis, uint[] memory aprs, uint[] memory lastSurfRewardBlocks, uint[2][] memory accTokensPerShares, uint[17][] memory metadatas) {\n        (tokens, lpTokens, isUnis, aprs, lastSurfRewardBlocks, accTokensPerShares) = _getAllPoolData();\n        metadatas = _getAllPoolMetadataFor(_user);\n    }\n\n    // Internal view function to get the current price of SURF on Uniswap\n    function _getSurfPrice() internal view returns (uint256 surfPrice) {\n        uint256 surfBalance = surf.balanceOf(surfPoolAddress);\n        if (surfBalance \u003e 0) {\n            surfPrice = 10**18 * weth.balanceOf(surfPoolAddress) / surfBalance;\n        }\n    }\n\n    // View function to show all relevant platform info on the frontend\n    function getAllInfoFor(address _user) external view returns (bool poolActive, uint256[8] memory info) {\n        poolActive = surfPoolActive;\n        info[0] = blocksUntilLaunch();\n        info[1] = blocksUntilSurfPoolCanBeActivated();\n        info[2] = blocksUntilSoftLaunchEnds();\n        info[3] = surf.totalSupply();\n        info[4] = _getSurfPrice();\n        if (surfPoolActive) {\n            info[5] = IERC20(surfPoolAddress).balanceOf(address(surf));\n        }\n        info[6] = surfSentToWhirlpool;\n        info[7] = surf.balanceOf(_user);\n    }\n\n    // View function to see the number of blocks remaining until launch on the frontend\n    function blocksUntilLaunch() public view returns (uint256) {\n        if (block.number \u003e= startBlock) return 0;\n        else return startBlock.sub(block.number);\n    }\n\n    // View function to see the number of blocks remaining until the SURF pool can be activated on the frontend\n    function blocksUntilSurfPoolCanBeActivated() public view returns (uint256) {\n        uint256 surfPoolActivationBlock = startBlock + SOFT_LAUNCH_DURATION.div(2);\n        if (block.number \u003e= surfPoolActivationBlock) return 0;\n        else return surfPoolActivationBlock.sub(block.number);\n    }\n\n    // View function to see the number of blocks remaining until the Soft Launch ends on the frontend\n    function blocksUntilSoftLaunchEnds() public view returns (uint256) {\n        uint256 softLaunchEndBlock = startBlock + SOFT_LAUNCH_DURATION;\n        if (block.number \u003e= softLaunchEndBlock) return 0;\n        else return softLaunchEndBlock.sub(block.number);\n    }\n\n    // Update reward variables for all pools. Be careful of gas spending!\n    function massUpdatePools() public {\n        uint256 length = poolInfo.length;\n        for (uint256 pid = (surfPoolActive == true ? 0 : 1); pid \u003c length; ++pid) {\n            updatePool(pid);\n        }\n    }\n\n    // Update reward variables of the given pool to be up-to-date.\n    function updatePool(uint256 _pid) public {\n        require(msg.sender == tx.origin || msg.sender == owner() || contractWhitelist[msg.sender] == true, \"no contracts\"); // Prevent flash loan attacks that manipulate prices.\n        \n        PoolInfo storage pool = poolInfo[_pid];\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        // Handle the UNI staking rewards contract for the LP token if one exists.\n        // The SURF-ETH pool would break by using the UNI staking rewards contract if one is made for it so it will be ignored\n        if (_pid != 0) {\n            // Check to see if the LP token has a UNI staking rewards contract to forward deposits to so that users can earn both SURF and UNI\n            if (pool.uniStakeContract == address(0)) {\n                (address uniStakeContract,) = uniStakingFactory.stakingRewardsInfoByStakingToken(address(pool.lpToken));\n\n                // If a UNI staking rewards contract exists then transfer all of the LP tokens to it to start earning UNI\n                if (uniStakeContract != address(0)) {\n                    pool.uniStakeContract = uniStakeContract;\n\n                    if (lpSupply \u003e 0) {\n                        pool.lpToken.safeApprove(uniStakeContract, 0);\n                        pool.lpToken.safeApprove(uniStakeContract, lpSupply);\n                        IStakingRewards(pool.uniStakeContract).stake(lpSupply);\n                    }\n                }\n            }\n\n            // A UNI staking rewards contract for this LP token is being used so get any pending UNI rewards\n            if (pool.uniStakeContract != address(0)) {\n                uint256 pendingUniTokens = IStakingRewards(pool.uniStakeContract).earned(address(this));\n                if (pendingUniTokens \u003e 0) {\n                    uint256 uniBalanceBefore = uniToken.balanceOf(address(this));\n                    IStakingRewards(pool.uniStakeContract).getReward();\n                    uint256 uniBalanceAfter = uniToken.balanceOf(address(this));\n                    pendingUniTokens = uniBalanceAfter.sub(uniBalanceBefore);\n                    pool.accUniPerShare = pool.accUniPerShare.add(pendingUniTokens.mul(1e12).div(lpSupply));\n                }\n            }\n        }\n\n        // Only update the pool if the max SURF supply hasn\u0027t been hit\n        if (surf.maxSupplyHit() != true) {\n            \n            if ((block.number \u003c= pool.lastSurfRewardBlock) || (_pid == 0 \u0026\u0026 surfPoolActive != true)) {\n                return;\n            }\n            if (lpSupply == 0) {\n                pool.lastSurfRewardBlock = block.number;\n                return;\n            }\n\n            uint256 surfReward = _calculateSurfReward(_pid, lpSupply);\n\n            // Make sure that surfReward won\u0027t push the total supply of SURF past surf.MAX_SUPPLY()\n            uint256 surfTotalSupply = surf.totalSupply();\n            if (surfTotalSupply.add(surfReward) \u003e= surf.MAX_SUPPLY()) {\n                surfReward = surf.MAX_SUPPLY().sub(surfTotalSupply);\n            }\n\n            // surf.mint(devAddress, surfReward.div(10)); Not minting 10% to the devs like Sushi, Sashimi, and Takeout do\n\n            if (surfReward \u003e 0) {\n                surf.mint(address(this), surfReward);\n                pool.accSurfPerShare = pool.accSurfPerShare.add(surfReward.mul(1e12).div(lpSupply));\n                pool.lastSurfRewardBlock = block.number;\n            }\n\n            if (surf.maxSupplyHit() == true) {\n                whirlpool.activate();\n            }\n        }\n    }\n\n    // Internal view function to get the amount of LP tokens staked in the specified pool\n    function _getPoolSupply(uint256 _pid) internal view returns (uint256 lpSupply) {\n        PoolInfo memory pool = poolInfo[_pid];\n\n        if (pool.uniStakeContract != address(0)) {\n            lpSupply = IStakingRewards(pool.uniStakeContract).balanceOf(address(this));\n        } else {\n            lpSupply = pool.lpToken.balanceOf(address(this));\n        }\n    }\n\n    // Deposits LP tokens in the specified pool to start earning the user SURF\n    function deposit(uint256 _pid, uint256 _amount) external {\n        depositFor(_pid, msg.sender, _amount);\n    }\n\n    // Deposits LP tokens in the specified pool on behalf of another user\n    function depositFor(uint256 _pid, address _user, uint256 _amount) public {\n        require(msg.sender == tx.origin || contractWhitelist[msg.sender] == true, \"no contracts\");\n        require(surf.maxSupplyHit() != true, \"pools closed\");\n        require(_pid != 0 || surfPoolActive == true, \"surf pool not active\");\n        require(_amount \u003e 0, \"deposit something\");\n\n        updatePool(_pid);\n\n        PoolInfo storage pool = poolInfo[_pid];\n        UserInfo storage user = userInfo[_pid][_user];\n\n        // The sender needs to give approval to the Tito contract for the specified amount of the LP token first\n        pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);\n\n        // Claim any pending SURF and UNI\n        _claimRewardsFromPool(_pid, _user);\n        \n        // Each pool has a 10% staking fee. If staking in the SURF-ETH pool, 100% of the fee gets permanently locked in the SURF contract (gives SURF liquidity forever).\n        // If staking in any other pool, 50% of the fee is used to buyback SURF which is sent to the Whirlpool staking contract where it will start getting distributed to stakers after the max supply is hit, and 50% goes to the team.\n        // The team is never minted or rewarded SURF for any reason to keep things as fair as possible.\n        uint256 stakingFeeAmount = _amount.div(10);\n        uint256 remainingUserAmount = _amount.sub(stakingFeeAmount);\n\n        // If a UNI staking rewards contract is available, use it\n        if (pool.uniStakeContract != address(0)) {\n            pool.lpToken.safeApprove(pool.uniStakeContract, 0);\n            pool.lpToken.safeApprove(pool.uniStakeContract, remainingUserAmount);\n            IStakingRewards(pool.uniStakeContract).stake(remainingUserAmount);\n        }\n\n        // The user is depositing to the SURF-ETH pool so permanently lock all of the LP tokens from the staking fee in the SURF contract\n        if (_pid == 0) {\n            pool.lpToken.transfer(address(surf), stakingFeeAmount);\n        } else {\n            uint256 ethBalanceBeforeSwap = address(this).balance;\n\n            // Remove the liquidity from the pool\n            uint256 deadline = block.timestamp + 5 minutes;\n            pool.lpToken.safeApprove(address(uniswapRouter), 0);\n            pool.lpToken.safeApprove(address(uniswapRouter), stakingFeeAmount);\n            uniswapRouter.removeLiquidityETHSupportingFeeOnTransferTokens(address(pool.token), stakingFeeAmount, 0, 0, address(this), deadline);\n\n            // Swap the ERC-20 token for ETH\n            uint256 tokensToSwap = pool.token.balanceOf(address(this));\n            require(tokensToSwap \u003e 0, \"bad token swap\");\n            address[] memory poolPath = new address[](2);\n            poolPath[0] = address(pool.token);\n            poolPath[1] = address(weth);\n            pool.token.safeApprove(address(uniswapRouter), 0);\n            pool.token.safeApprove(address(uniswapRouter), tokensToSwap);\n            uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(tokensToSwap, 0, poolPath, address(this), deadline);\n\n            uint256 ethBalanceAfterSwap = address(this).balance;\n            uint256 ethReceivedFromStakingFee;\n            uint256 teamFeeAmount;\n\n            // If surfPoolActive == true then perform a buyback of SURF using all of the ETH in the contract and then send it to the Whirlpool staking contract. Otherwise, the ETH will be used to seed the initial liquidity in the SURF-ETH Uniswap pool when activateSurfPool is called\n            if (surfPoolActive == true) {\n                require(ethBalanceAfterSwap \u003e 0, \"bad eth swap\");\n\n                teamFeeAmount = ethBalanceAfterSwap.div(2);\n                ethReceivedFromStakingFee = ethBalanceAfterSwap.sub(teamFeeAmount);\n\n                // The SURF-ETH pool is active, so let\u0027s use the ETH to buyback SURF and send it to the Whirlpool staking contract\n                uint256 surfBought = _buySurf(ethReceivedFromStakingFee);\n\n                // Send the SURF rewards to the Whirlpool staking contract\n                surfSentToWhirlpool += surfBought;\n                _safeSurfTransfer(address(whirlpool), surfBought);\n            } else {\n                ethReceivedFromStakingFee = ethBalanceAfterSwap.sub(ethBalanceBeforeSwap);\n                require(ethReceivedFromStakingFee \u003e 0, \"bad eth swap\");\n\n                teamFeeAmount = ethReceivedFromStakingFee.div(2);\n            }\n\n            if (teamFeeAmount \u003e 0) devAddress.transfer(teamFeeAmount);\n        }\n\n        // Add the remaining amount to the user\u0027s staked balance\n        uint256 _currentRewardDebt = 0;\n        uint256 _currentUniRewardDebt = 0;\n        if (surfPoolActive != true) {\n            _currentRewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(user.rewardDebt);\n            _currentUniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n        }\n        user.staked = user.staked.add(remainingUserAmount);\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(_currentRewardDebt);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12).sub(_currentUniRewardDebt);\n\n        emit Deposit(_user, _pid, _amount);\n    }\n\n    // Internal function that buys back SURF with the amount of ETH specified\n    function _buySurf(uint256 _amount) internal returns (uint256 surfBought) {\n        uint256 ethBalance = address(this).balance;\n        if (_amount \u003e ethBalance) _amount = ethBalance;\n        if (_amount \u003e 0) {\n            uint256 deadline = block.timestamp + 5 minutes;\n            address[] memory surfPath = new address[](2);\n            surfPath[0] = address(weth);\n            surfPath[1] = address(surf);\n            uint256[] memory amounts = uniswapRouter.swapExactETHForTokens{value: _amount}(0, surfPath, address(this), deadline);\n            surfBought = amounts[1];\n        }\n        if (surfBought \u003e 0) emit SurfBuyback(msg.sender, _amount, surfBought);\n    }\n\n    // Internal function to claim earned SURF and UNI from Tito. Claiming won\u0027t work until surfPoolActive == true\n    function _claimRewardsFromPool(uint256 _pid, address _user) internal {\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo storage user = userInfo[_pid][_user];\n\n        if (surfPoolActive != true || user.staked == 0) return;\n\n        uint256 userUniPending = user.staked.mul(pool.accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n        uint256 uniBalance = uniToken.balanceOf(address(this));\n        if (userUniPending \u003e uniBalance) userUniPending = uniBalance;\n        if (userUniPending \u003e 0) {\n            user.uniClaimed += userUniPending;\n            uniToken.transfer(_user, userUniPending);\n        }\n\n        uint256 userSurfPending = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(user.rewardDebt);\n        if (userSurfPending \u003e 0) {\n            user.claimed += userSurfPending;\n            _safeSurfTransfer(_user, userSurfPending);\n        }\n\n        if (userSurfPending \u003e 0 || userUniPending \u003e 0) {\n            emit Claim(_user, _pid, userSurfPending, userUniPending);\n        }\n    }\n\n    // Claim all earned SURF and UNI from a single pool. Claiming won\u0027t work until surfPoolActive == true\n    function claim(uint256 _pid) public {\n        require(surfPoolActive == true, \"surf pool not active\");\n        updatePool(_pid);\n        _claimRewardsFromPool(_pid, msg.sender);\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        PoolInfo memory pool = poolInfo[_pid];\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12);\n    }\n\n    // Claim all earned SURF and UNI from all pools. Claiming won\u0027t work until surfPoolActive == true\n    function claimAll() public {\n        require(surfPoolActive == true, \"surf pool not active\");\n\n        uint256 totalPendingSurfAmount = 0;\n        uint256 totalPendingUniAmount = 0;\n        \n        uint256 length = poolInfo.length;\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            UserInfo storage user = userInfo[pid][msg.sender];\n\n            if (user.staked \u003e 0) {\n                updatePool(pid);\n\n                PoolInfo storage pool = poolInfo[pid];\n                uint256 accSurfPerShare = pool.accSurfPerShare;\n                uint256 accUniPerShare = pool.accUniPerShare;\n\n                uint256 pendingPoolSurfRewards = user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n                user.claimed += pendingPoolSurfRewards;\n                totalPendingSurfAmount = totalPendingSurfAmount.add(pendingPoolSurfRewards);\n                user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n\n                uint256 pendingPoolUniRewards = user.staked.mul(accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n                user.uniClaimed += pendingPoolUniRewards;\n                totalPendingUniAmount = totalPendingUniAmount.add(pendingPoolUniRewards);\n                user.uniRewardDebt = user.staked.mul(accUniPerShare).div(1e12);\n            }\n        }\n\n        require(totalPendingSurfAmount \u003e 0 || totalPendingUniAmount \u003e 0, \"nothing to claim\");\n\n        uint256 uniBalance = uniToken.balanceOf(address(this));\n        if (totalPendingUniAmount \u003e uniBalance) totalPendingUniAmount = uniBalance;\n        if (totalPendingUniAmount \u003e 0) uniToken.transfer(msg.sender, totalPendingUniAmount);\n\n        if (totalPendingSurfAmount \u003e 0) _safeSurfTransfer(msg.sender, totalPendingSurfAmount);\n\n        emit ClaimAll(msg.sender, totalPendingSurfAmount, totalPendingUniAmount);\n    }\n\n    // Withdraw LP tokens and earned SURF from Tito. Withdrawing won\u0027t work until surfPoolActive == true\n    function withdraw(uint256 _pid, uint256 _amount) public {\n        require(surfPoolActive == true, \"surf pool not active\");\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        require(_amount \u003e 0 \u0026\u0026 user.staked \u003e= _amount, \"withdraw: not good\");\n        \n        updatePool(_pid);\n\n        // Claim any pending SURF and UNI\n        _claimRewardsFromPool(_pid, msg.sender);\n\n        PoolInfo memory pool = poolInfo[_pid];\n\n        // If a UNI staking rewards contract is in use, withdraw from it\n        if (pool.uniStakeContract != address(0)) {\n            IStakingRewards(pool.uniStakeContract).withdraw(_amount);\n        }\n\n        user.staked = user.staked.sub(_amount);\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12);\n\n        pool.lpToken.safeTransfer(address(msg.sender), _amount);\n        emit Withdraw(msg.sender, _pid, _amount);\n    }\n\n    // Convenience function to allow users to migrate all of their staked SURF-ETH LP tokens from Tito to the Whirlpool staking contract after the max supply is hit. Migrating won\u0027t work until whirlpool.active() == true\n    function migrateSURFLPtoWhirlpool() public {\n        require(whirlpool.active() == true, \"whirlpool not active\");\n        UserInfo storage user = userInfo[0][msg.sender];\n        uint256 amountToMigrate = user.staked;\n        require(amountToMigrate \u003e 0, \"migrate: not good\");\n        \n        updatePool(0);\n\n        // Claim any pending SURF\n        _claimRewardsFromPool(0, msg.sender);\n\n        user.staked = 0;\n        user.rewardDebt = 0;\n\n        poolInfo[0].lpToken.safeApprove(address(whirlpool), 0);\n        poolInfo[0].lpToken.safeApprove(address(whirlpool), amountToMigrate);\n        whirlpool.stakeFor(msg.sender, amountToMigrate);\n        emit Withdraw(msg.sender, 0, amountToMigrate);\n    }\n\n    // Withdraw without caring about rewards. EMERGENCY ONLY.\n    function emergencyWithdraw(uint256 _pid) public {\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        uint256 staked = user.staked;\n        require(staked \u003e 0, \"no tokens\");\n\n        PoolInfo memory pool = poolInfo[_pid];\n\n        // If a UNI staking rewards contract is in use, withdraw from it\n        if (pool.uniStakeContract != address(0)) {\n            IStakingRewards(pool.uniStakeContract).withdraw(staked);\n        }\n        \n        user.staked = 0;\n        user.rewardDebt = 0;\n        user.uniRewardDebt = 0;\n\n        pool.lpToken.safeTransfer(address(msg.sender), staked);\n        emit EmergencyWithdraw(msg.sender, _pid, staked);\n    }\n\n    // Internal function to safely transfer SURF in case there is a rounding error\n    function _safeSurfTransfer(address _to, uint256 _amount) internal {\n        uint256 surfBalance = surf.balanceOf(address(this));\n        if (_amount \u003e surfBalance) _amount = surfBalance;\n        surf.transfer(_to, _amount);\n    }\n\n    // Creates the SURF-ETH Uniswap pool and adds the initial liqudity that will be permanently locked. Can be called by anyone, but no sooner than 500 blocks after launch. \n    function activateSurfPool() public {\n        require(surfPoolActive == false, \"already active\");\n        require(block.number \u003e startBlock + SOFT_LAUNCH_DURATION.div(2), \"too soon\");\n        uint256 initialEthLiquidity = address(this).balance;\n        require(initialEthLiquidity \u003e 0, \"need ETH\");\n\n        massUpdatePools();\n\n        // The ETH raised from the staking fees collected before surfPoolActive == true is used to seed the ETH side of the SURF-ETH Uniswap pool.\n        // This means that the higher the staking volume during the first 500 blocks, the higher the initial price of SURF\n        if (donatedETH \u003e 0 \u0026\u0026 donatedETH \u003c initialEthLiquidity) initialEthLiquidity = initialEthLiquidity.sub(donatedETH);\n\n        // Mint 1,000,000 new SURF to seed the SURF liquidity in the SURF-ETH Uniswap pool\n        uint256 initialSurfLiquidity = 1000000 * 10**18;\n        surf.mint(address(this), initialSurfLiquidity);\n\n        // Add the liquidity to the SURF-ETH Uniswap pool\n        surf.approve(address(uniswapRouter), initialSurfLiquidity);\n        ( , , uint256 lpTokensReceived) = uniswapRouter.addLiquidityETH{value: initialEthLiquidity}(address(surf), initialSurfLiquidity, 0, 0, address(this), block.timestamp + 5 minutes);\n\n        // Activate the SURF-ETH pool\n        initialSurfPoolETH = initialEthLiquidity;\n        surfPoolActive = true;\n\n        // Permanently lock the LP tokens in the SURF contract\n        IERC20(surfPoolAddress).transfer(address(surf), lpTokensReceived);\n\n        // Buy SURF with all of the donatedETH from partner projects. This SURF will be sent to the Whirlpool staking contract and will start getting distributed to all stakers when the max supply is hit\n        uint256 donatedAmount = donatedETH;\n        uint256 ethBalance = address(this).balance;\n        if (donatedAmount \u003e ethBalance) donatedAmount = ethBalance;\n        if (donatedAmount \u003e 0) {\n            uint256 surfBought = _buySurf(donatedAmount);\n\n            // Send the SURF rewards to the Whirlpool staking contract\n            surfSentToWhirlpool += surfBought;\n            _safeSurfTransfer(address(whirlpool), surfBought);\n            donatedETH = 0;\n        }\n\n        emit SurfPoolActive(msg.sender, initialSurfLiquidity, initialEthLiquidity);\n    }\n\n    // For use by partner teams that are donating to the SURF community. The funds will be used to purchase SURF tokens which will be distributed to stakers once the max supply is hit\n    function donate(address _lpToken) public payable {\n        require(msg.value \u003e= minimumDonationAmount);\n        require(donaters[_lpToken] == address(0));\n\n        donatedETH = donatedETH.add(msg.value);\n        donaters[_lpToken] = msg.sender;\n        donations[_lpToken] = msg.value;\n    }\n\n    // For use by partner teams that donated to the SURF community. The funds can be removed if a beach wasn\u0027t created for the specified lp token (meaning the SURF team didn\u0027t hold up their end of the agreement)\n    function removeDonation(address _lpToken) public {\n        require(block.number \u003c startBlock); // Donations can only be removed if the beach hasn\u0027t been added by the startBlock\n        \n        address returnAddress = donaters[_lpToken];\n        require(msg.sender == returnAddress);\n        \n        uint256 donationAmount = donations[_lpToken];\n        require(donationAmount \u003e 0);\n        \n        uint256 ethBalance = address(this).balance;\n        require(donationAmount \u003c= ethBalance);\n\n        // Only refund the donation if the beach wasn\u0027t created\n        require(existingPools[_lpToken] != true);\n\n        donatedETH = donatedETH.sub(donationAmount);\n        donaters[_lpToken] = address(0);\n        donations[_lpToken] = 0;\n\n        msg.sender.transfer(donationAmount);\n    }\n\n    //////////////////////////\n    // Governance Functions //\n    //////////////////////////\n    // The following functions can only be called by the owner (the SURF token holder governance contract)\n\n    // Sets the address of the Whirlpool staking contract that bought SURF gets sent to for distribution to stakers once the max supply is hit\n    function setWhirlpoolContract(Whirlpool _whirlpool) public onlyOwner {\n        whirlpool = _whirlpool;\n    }\n\n    // Add a new LP Token pool\n    function addPool(address _token, address _lpToken, uint256 _apr, bool _requireDonation) public onlyOwner {\n        require(surf.maxSupplyHit() != true);\n        require(existingPools[_lpToken] != true, \"pool exists\");\n        require(_requireDonation != true || donations[_lpToken] \u003e= minimumDonationAmount, \"must donate\");\n\n        _addPool(_token, _lpToken);\n        if (_apr != DEFAULT_APR) poolInfo[poolInfo.length-1].apr = _apr;\n    }\n\n    // Update the given pool\u0027s APR\n    function setApr(uint256 _pid, uint256 _apr) public onlyOwner {\n        require(surf.maxSupplyHit() != true);\n        updatePool(_pid);\n        poolInfo[_pid].apr = _apr;\n    }\n\n    // Add a contract to the whitelist so that it can interact with Tito. This is needed for the Aegis pool contract to be able to stake on behalf of everyone in the pool.\n    // We want limited interaction from contracts due to the growing \"flash loan\" trend that can be used to dramatically manipulate a token\u0027s price in a single block.\n    function addToWhitelist(address _contractAddress) public onlyOwner {\n        contractWhitelist[_contractAddress] = true;\n    }\n\n    // Remove a contract from the whitelist\n    function removeFromWhitelist(address _contractAddress) public onlyOwner {\n        contractWhitelist[_contractAddress] = false;\n    }\n\n}"},"UniStakingInterfaces.sol":{"content":"pragma solidity ^0.6.12;\n\ninterface StakingRewardsFactory {\n    function stakingRewardsInfoByStakingToken(address) external view returns (address, uint256);\n}\n\ninterface IStakingRewards {\n    // Views\n    function lastTimeRewardApplicable() external view returns (uint256);\n\n    function rewardPerToken() external view returns (uint256);\n\n    function earned(address account) external view returns (uint256);\n\n    function getRewardForDuration() external view returns (uint256);\n\n    function totalSupply() external view returns (uint256);\n\n    function balanceOf(address account) external view returns (uint256);\n\n    // Mutative\n\n    function stake(uint256 amount) external;\n\n    function withdraw(uint256 amount) external;\n\n    function getReward() external;\n\n    function exit() external;\n}"},"Whirlpool.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./SafeERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./IUniswapV2Router02.sol\u0027;\nimport \u0027./SURF.sol\u0027;\nimport \u0027./Tito.sol\u0027;\n\n// The Whirlpool staking contract becomes active after the max supply it hit, and is where SURF-ETH LP token stakers will continue to receive dividends from other projects in the SURF ecosystem\ncontract Whirlpool is Ownable {\n    using SafeMath for uint256;\n    using SafeERC20 for IERC20;\n\n    // Info of each user\n    struct UserInfo {\n        uint256 staked; // How many SURF-ETH LP tokens the user has staked\n        uint256 rewardDebt; // Reward debt. Works the same as in the Tito contract\n        uint256 claimed; // Tracks the amount of SURF claimed by the user\n    }\n\n    // The SURF TOKEN!\n    SURF public surf;\n    // The Tito contract\n    Tito public tito;\n    // The SURF-ETH Uniswap LP token\n    IERC20 public surfPool;\n    // The Uniswap v2 Router\n    IUniswapV2Router02 public uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);\n    // WETH\n    IERC20 public weth;\n\n    // Info of each user that stakes SURF-ETH LP tokens\n    mapping (address =\u003e UserInfo) public userInfo;\n    // The amount of SURF sent to this contract before it became active\n    uint256 public initialSurfReward = 0;\n    // 1% of the initialSurfReward will be rewarded to stakers per day for 100 days\n    uint256 public initialSurfRewardPerDay;\n    // How often the initial 1% payouts can be processed\n    uint256 public constant INITIAL_PAYOUT_INTERVAL = 24 hours;\n    // The unstaking fee that is used to increase locked liquidity and reward Whirlpool stakers (1 = 0.1%). Defaults to 10%\n    uint256 public unstakingFee = 100;\n    // The amount of SURF-ETH LP tokens kept by the unstaking fee that will be converted to SURF and distributed to stakers (1 = 0.1%). Defaults to 50%\n    uint256 public unstakingFeeConvertToSurfAmount = 500;\n    // When the first 1% payout can be processed (timestamp). It will be 24 hours after the Whirlpool contract is activated\n    uint256 public startTime;\n    // When the last 1% payout was processed (timestamp)\n    uint256 public lastPayout;\n    // The total amount of pending SURF available for stakers to claim\n    uint256 public totalPendingSurf;\n    // Accumulated SURFs per share, times 1e12.\n    uint256 public accSurfPerShare;\n    // The total amount of SURF-ETH LP tokens staked in the contract\n    uint256 public totalStaked;\n    // Becomes true once the \u0027activate\u0027 function called by the Tito contract when the max SURF supply is hit\n    bool public active = false;\n\n    event Stake(address indexed user, uint256 amount);\n    event Claim(address indexed user, uint256 surfAmount);\n    event Withdraw(address indexed user, uint256 amount);\n    event SurfRewardAdded(address indexed user, uint256 surfReward);\n    event EthRewardAdded(address indexed user, uint256 ethReward);\n\n    constructor(SURF _surf, Tito _tito) public {\n        tito = _tito;\n        surf = _surf;\n        surfPool = IERC20(tito.surfPoolAddress());\n        weth = IERC20(uniswapRouter.WETH());\n    }\n\n    receive() external payable {\n        emit EthRewardAdded(msg.sender, msg.value);\n    }\n\n    function activate() public {\n        require(active != true, \"already active\");\n        require(surf.maxSupplyHit() == true, \"too soon\");\n\n        active = true;\n\n        // Now that the Whirlpool staking contract is active, reward 1% of the initialSurfReward per day for 100 days\n        startTime = block.timestamp + INITIAL_PAYOUT_INTERVAL; // The first payout can be processed 24 hours after activation\n        lastPayout = startTime;\n        initialSurfRewardPerDay = initialSurfReward.div(100);\n    }\n\n    // The _transfer function in the SURF contract calls this to let the Whirlpool contract know that it received the specified amount of SURF to be distributed to stakers \n    function addSurfReward(address _from, uint256 _amount) public {\n        require(msg.sender == address(surf), \"not surf contract\");\n        require(tito.surfPoolActive() == true, \"no surf pool\");\n        require(_amount \u003e 0, \"no surf\");\n\n        if (active != true || totalStaked == 0) {\n            initialSurfReward = initialSurfReward.add(_amount);\n        } else {\n            totalPendingSurf = totalPendingSurf.add(_amount);\n            accSurfPerShare = accSurfPerShare.add(_amount.mul(1e12).div(totalStaked));\n        }\n\n        emit SurfRewardAdded(_from, _amount);\n    }\n\n    // Allows external sources to add ETH to the contract which is used to buy and then distribute SURF to stakers\n    function addEthReward() public payable {\n        require(tito.surfPoolActive() == true, \"no surf pool\");\n\n        // We will purchase SURF with all of the ETH in the contract in case some was sent directly to the contract instead of using addEthReward\n        uint256 ethBalance = address(this).balance;\n        require(ethBalance \u003e 0, \"no eth\");\n\n        // Use the ETH to buyback SURF which will be distributed to stakers\n        _buySurf(ethBalance);\n\n        // The _transfer function in the SURF contract calls the Whirlpool contract\u0027s updateSurfReward function so we don\u0027t need to update the balances after buying the SURF\n        emit EthRewardAdded(msg.sender, msg.value);\n    }\n\n    // Internal function to buy back SURF with the amount of ETH specified\n    function _buySurf(uint256 _amount) internal {\n        uint256 deadline = block.timestamp + 5 minutes;\n        address[] memory surfPath = new address[](2);\n        surfPath[0] = address(weth);\n        surfPath[1] = address(surf);\n        uniswapRouter.swapExactETHForTokens{value: _amount}(0, surfPath, address(this), deadline);\n    }\n\n    // Handles paying out the initialSurfReward over 100 days\n    function _processInitialPayouts() internal {\n        if (active != true || block.timestamp \u003c startTime || initialSurfReward == 0 || totalStaked == 0) return;\n\n        // How many days since last payout?\n        uint256 daysSinceLastPayout = (block.timestamp - lastPayout) / INITIAL_PAYOUT_INTERVAL;\n\n        // If less than 1, don\u0027t do anything\n        if (daysSinceLastPayout == 0) return;\n\n        // Work out how many payouts have been missed\n        uint256 nextPayoutNumber = (block.timestamp - startTime) / INITIAL_PAYOUT_INTERVAL;\n        uint256 previousPayoutNumber = nextPayoutNumber - daysSinceLastPayout;\n\n        // Calculate how much additional reward we have to hand out\n        uint256 surfReward = rewardAtPayout(nextPayoutNumber) - rewardAtPayout(previousPayoutNumber);\n        if (surfReward \u003e initialSurfReward) surfReward = initialSurfReward;\n        initialSurfReward = initialSurfReward.sub(surfReward);\n\n        // Payout the surfReward to the stakers\n        totalPendingSurf = totalPendingSurf.add(surfReward);\n        accSurfPerShare = accSurfPerShare.add(surfReward.mul(1e12).div(totalStaked));\n\n        // Update lastPayout time\n        lastPayout += (daysSinceLastPayout * INITIAL_PAYOUT_INTERVAL);\n    }\n\n    // Handles claiming the user\u0027s pending SURF rewards\n    function _claimReward(address _user) internal {\n        UserInfo storage user = userInfo[_user];\n        if (user.staked \u003e 0) {\n            uint256 pendingSurfReward = user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n            if (pendingSurfReward \u003e 0) {\n                totalPendingSurf = totalPendingSurf.sub(pendingSurfReward);\n                user.claimed += pendingSurfReward;\n                _safeSurfTransfer(_user, pendingSurfReward);\n                emit Claim(_user, pendingSurfReward);\n            }\n        }\n    }\n\n    // Stake SURF-ETH LP tokens to get rewarded with more SURF\n    function stake(uint256 _amount) public {\n        stakeFor(msg.sender, _amount);\n    }\n\n    // Stake SURF-ETH LP tokens on behalf of another address\n    function stakeFor(address _user, uint256 _amount) public {\n        require(active == true, \"not active\");\n        require(_amount \u003e 0, \"stake something\");\n\n        _processInitialPayouts();\n\n        // Claim any pending SURF\n        _claimReward(_user);\n\n        surfPool.safeTransferFrom(address(msg.sender), address(this), _amount);\n\n        UserInfo storage user = userInfo[_user];\n        totalStaked = totalStaked.add(_amount);\n        user.staked = user.staked.add(_amount);\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n        emit Stake(_user, _amount);\n    }\n\n    // Claim earned SURF. Claiming won\u0027t work until active == true\n    function claim() public {\n        require(active == true, \"not active\");\n        UserInfo storage user = userInfo[msg.sender];\n        require(user.staked \u003e 0, \"no stake\");\n        \n        _processInitialPayouts();\n\n        // Claim any pending SURF\n        _claimReward(msg.sender);\n\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n    }\n\n    // Unstake and withdraw SURF-ETH LP tokens and any pending SURF rewards. There is a 10% unstaking fee, meaning the user will only receive 90% of their LP tokens back.\n    // For the LP tokens kept by the unstaking fee, 50% will get locked forever in the SURF contract, and 50% will get converted to SURF and distributed to stakers.\n    function withdraw(uint256 _amount) public {\n        require(active == true, \"not active\");\n        UserInfo storage user = userInfo[msg.sender];\n        require(_amount \u003e 0 \u0026\u0026 user.staked \u003e= _amount, \"withdraw: not good\");\n        \n        _processInitialPayouts();\n\n        uint256 unstakingFeeAmount = _amount.mul(unstakingFee).div(1000);\n        uint256 remainingUserAmount = _amount.sub(unstakingFeeAmount);\n\n        // Half of the LP tokens kept by the unstaking fee will be locked forever in the SURF contract, the other half will be converted to SURF and distributed to stakers\n        uint256 lpTokensToConvertToSurf = unstakingFeeAmount.mul(unstakingFeeConvertToSurfAmount).div(1000);\n        uint256 lpTokensToLock = unstakingFeeAmount.sub(lpTokensToConvertToSurf);\n\n        // Remove the liquidity from the Uniswap SURF-ETH pool and buy SURF with the ETH received\n        // The _transfer function in the SURF.sol contract automatically calls whirlpool.addSurfReward() so we don\u0027t have to in this function\n        if (lpTokensToConvertToSurf \u003e 0) {\n            surfPool.safeApprove(address(uniswapRouter), lpTokensToConvertToSurf);\n            uniswapRouter.removeLiquidityETHSupportingFeeOnTransferTokens(address(surf), lpTokensToConvertToSurf, 0, 0, address(this), block.timestamp + 5 minutes);\n            addEthReward();\n        }\n\n        // Permanently lock the LP tokens in the SURF contract\n        if (lpTokensToLock \u003e 0) surfPool.transfer(address(surf), lpTokensToLock);\n\n        // Claim any pending SURF\n        _claimReward(msg.sender);\n\n        totalStaked = totalStaked.sub(_amount);\n        user.staked = user.staked.sub(_amount);\n        surfPool.safeTransfer(address(msg.sender), remainingUserAmount);\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n        emit Withdraw(msg.sender, remainingUserAmount);\n    }\n\n    // Internal function to safely transfer SURF in case there is a rounding error\n    function _safeSurfTransfer(address _to, uint256 _amount) internal {\n        uint256 surfBal = surf.balanceOf(address(this));\n        if (_amount \u003e surfBal) {\n            surf.transfer(_to, surfBal);\n        } else {\n            surf.transfer(_to, _amount);\n        }\n    }\n\n    // Sets the unstaking fee. Can\u0027t be higher than 50%. _convertToSurfAmount is the % of the LP tokens from the unstaking fee that will be converted to SURF and distributed to stakers.\n    // unstakingFee - unstakingFeeConvertToSurfAmount = The % of the LP tokens from the unstaking fee that will be permanently locked in the SURF contract\n    function setUnstakingFee(uint256 _unstakingFee, uint256 _convertToSurfAmount) public onlyOwner {\n        require(_unstakingFee \u003c= 500, \"over 50%\");\n        require(_convertToSurfAmount \u003c= 1000, \"bad amount\");\n        unstakingFee = _unstakingFee;\n        unstakingFeeConvertToSurfAmount = _convertToSurfAmount;\n    }\n\n    // Function to recover ERC20 tokens accidentally sent to the contract.\n    // SURF and SURF-ETH LP tokens (the only 2 ERC2O\u0027s that should be in this contract) can\u0027t be withdrawn this way.\n    function recoverERC20(address _tokenAddress) public onlyOwner {\n        require(_tokenAddress != address(surf) \u0026\u0026 _tokenAddress != address(surfPool));\n        IERC20 token = IERC20(_tokenAddress);\n        uint256 tokenBalance = token.balanceOf(address(this));\n        token.transfer(msg.sender, tokenBalance);\n    }\n\n    function payoutNumber() public view returns (uint256) {\n        if (block.timestamp \u003c startTime) return 0;\n\n        uint256 payout = (block.timestamp - startTime).div(INITIAL_PAYOUT_INTERVAL);\n        if (payout \u003e 100) return 100;\n        else return payout;\n    }\n\n    function timeUntilNextPayout() public view returns (uint256) {\n        if (initialSurfReward == 0) return 0;\n        else {\n            uint256 payout = payoutNumber();\n            uint256 nextPayout = startTime.add((payout + 1).mul(INITIAL_PAYOUT_INTERVAL));\n            return nextPayout - block.timestamp;\n        }\n    }\n\n    function rewardAtPayout(uint256 _payoutNumber) public view returns (uint256) {\n        if (_payoutNumber == 0) return 0;\n        return initialSurfRewardPerDay * _payoutNumber;\n    }\n\n    function getAllInfoFor(address _user) external view returns (bool isActive, uint256[12] memory info) {\n        isActive = active;\n        info[0] = surf.balanceOf(address(this));\n        info[1] = initialSurfReward;\n        info[2] = totalPendingSurf;\n        info[3] = startTime;\n        info[4] = lastPayout;\n        info[5] = totalStaked;\n        info[6] = surf.balanceOf(_user);\n        if (tito.surfPoolActive()) {\n            info[7] = surfPool.balanceOf(_user);\n            info[8] = surfPool.allowance(_user, address(this));\n        }\n        info[9] = userInfo[_user].staked;\n        info[10] = userInfo[_user].staked.mul(accSurfPerShare).div(1e12).sub(userInfo[_user].rewardDebt);\n        info[11] = userInfo[_user].claimed;\n    }\n\n}"}}

{"Address.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts\n        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned\n        // for accounts without code, i.e. `keccak256(\u0027\u0027)`\n        bytes32 codehash;\n        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { codehash := extcodehash(account) }\n        return (codehash != accountHash \u0026\u0026 codehash != 0x0);\n    }\n\n    /**\n     * @dev Replacement for Solidity\u0027s `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance \u003e= amount, \"Address: insufficient balance\");\n\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\n        (bool success, ) = recipient.call{ value: amount }(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain`call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n      return functionCall(target, data, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\n        return _functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {\n        require(address(this).balance \u003e= value, \"Address: insufficient balance for call\");\n        return _functionCallWithValue(target, data, value, errorMessage);\n    }\n\n    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {\n        require(isContract(target), \"Address: call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);\n        if (success) {\n            return returndata;\n        } else {\n            // Look for revert reason and bubble it up if present\n            if (returndata.length \u003e 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\n                // solhint-disable-next-line no-inline-assembly\n                assembly {\n                    let returndata_size := mload(returndata)\n                    revert(add(32, returndata), returndata_size)\n                }\n            } else {\n                revert(errorMessage);\n            }\n        }\n    }\n}"},"Context.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/GSN/Context.sol\n\n/*\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with GSN meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address payable) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes memory) {\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n        return msg.data;\n    }\n}"},"ERC20.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./Context.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\n\n// File: @openzeppelin/contracts/token/ERC20/ERC20.sol\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * We have followed general OpenZeppelin guidelines: functions revert instead\n * of returning `false` on failure. This behavior is nonetheless conventional\n * and does not conflict with the expectations of ERC20 applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn\u0027t required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract ERC20 is Context, IERC20 {\n    using SafeMath for uint256;\n\n    mapping (address =\u003e uint256) internal _balances;\n\n    mapping (address =\u003e mapping (address =\u003e uint256)) private _allowances;\n\n    uint256 private _totalSupply;\n\n    string private _name;\n    string private _symbol;\n    uint8 private _decimals;\n\n    /**\n     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with\n     * a default value of 18.\n     *\n     * To select a different value for {decimals}, use {_setupDecimals}.\n     *\n     * All three of these values are immutable: they can only be set once during\n     * construction.\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n        _decimals = 18;\n    }\n\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() public view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Returns the symbol of the token, usually a shorter version of the\n     * name.\n     */\n    function symbol() public view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns the number of decimals used to get its user representation.\n     * For example, if `decimals` equals `2`, a balance of `505` tokens should\n     * be displayed to a user as `5,05` (`505 / 10 ** 2`).\n     *\n     * Tokens usually opt for a value of 18, imitating the relationship between\n     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is\n     * called.\n     *\n     * NOTE: This information is only used for _display_ purposes: it in\n     * no way affects any of the arithmetic of the contract, including\n     * {IERC20-balanceOf} and {IERC20-transfer}.\n     */\n    function decimals() public view override returns (uint8) {\n        return _decimals;\n    }\n\n    /**\n     * @dev See {IERC20-totalSupply}.\n     */\n    function totalSupply() public view override returns (uint256) {\n        return _totalSupply;\n    }\n\n    /**\n     * @dev See {IERC20-balanceOf}.\n     */\n    function balanceOf(address account) public view override returns (uint256) {\n        return _balances[account];\n    }\n\n    /**\n     * @dev See {IERC20-transfer}.\n     *\n     * Requirements:\n     *\n     * - `recipient` cannot be the zero address.\n     * - the caller must have a balance of at least `amount`.\n     */\n    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(_msgSender(), recipient, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-allowance}.\n     */\n    function allowance(address owner, address spender) public view virtual override returns (uint256) {\n        return _allowances[owner][spender];\n    }\n\n    /**\n     * @dev See {IERC20-approve}.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function approve(address spender, uint256 amount) public virtual override returns (bool) {\n        _approve(_msgSender(), spender, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-transferFrom}.\n     *\n     * Emits an {Approval} event indicating the updated allowance. This is not\n     * required by the EIP. See the note at the beginning of {ERC20};\n     *\n     * Requirements:\n     * - `sender` and `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     * - the caller must have allowance for ``sender``\u0027s tokens of at least\n     * `amount`.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(sender, recipient, amount);\n        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"ERC20: transfer amount exceeds allowance\"));\n        return true;\n    }\n\n    /**\n     * @dev Atomically increases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\n        return true;\n    }\n\n    /**\n     * @dev Atomically decreases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `spender` must have allowance for the caller of at least\n     * `subtractedValue`.\n     */\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"ERC20: decreased allowance below zero\"));\n        return true;\n    }\n\n    /**\n     * @dev Moves tokens `amount` from `sender` to `recipient`.\n     *\n     * This is internal function is equivalent to {transfer}, and can be used to\n     * e.g. implement automatic token fees, slashing mechanisms, etc.\n     *\n     * Emits a {Transfer} event.\n     *\n     * Requirements:\n     *\n     * - `sender` cannot be the zero address.\n     * - `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     */\n    function _transfer(address sender, address recipient, uint256 amount) internal virtual {\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        _beforeTokenTransfer(sender, recipient, amount);\n\n        _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n        _balances[recipient] = _balances[recipient].add(amount);\n        emit Transfer(sender, recipient, amount);\n    }\n\n    /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n     * the total supply.\n     *\n     * Emits a {Transfer} event with `from` set to the zero address.\n     *\n     * Requirements\n     *\n     * - `to` cannot be the zero address.\n     */\n    function _mint(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: mint to the zero address\");\n\n        _beforeTokenTransfer(address(0), account, amount);\n\n        _totalSupply = _totalSupply.add(amount);\n        _balances[account] = _balances[account].add(amount);\n        emit Transfer(address(0), account, amount);\n    }\n\n    /**\n     * @dev Destroys `amount` tokens from `account`, reducing the\n     * total supply.\n     *\n     * Emits a {Transfer} event with `to` set to the zero address.\n     *\n     * Requirements\n     *\n     * - `account` cannot be the zero address.\n     * - `account` must have at least `amount` tokens.\n     */\n    function _burn(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: burn from the zero address\");\n\n        _beforeTokenTransfer(account, address(0), amount);\n\n        _balances[account] = _balances[account].sub(amount, \"ERC20: burn amount exceeds balance\");\n        _totalSupply = _totalSupply.sub(amount);\n        emit Transfer(account, address(0), amount);\n    }\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.\n     *\n     * This is internal function is equivalent to `approve`, and can be used to\n     * e.g. set automatic allowances for certain subsystems, etc.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `owner` cannot be the zero address.\n     * - `spender` cannot be the zero address.\n     */\n    function _approve(address owner, address spender, uint256 amount) internal virtual {\n        require(owner != address(0), \"ERC20: approve from the zero address\");\n        require(spender != address(0), \"ERC20: approve to the zero address\");\n\n        _allowances[owner][spender] = amount;\n        emit Approval(owner, spender, amount);\n    }\n\n    /**\n     * @dev Sets {decimals} to a value other than the default one of 18.\n     *\n     * WARNING: This function should only be called from the constructor. Most\n     * applications that interact with token contracts will not expect\n     * {decimals} to ever change, and may work incorrectly if it does.\n     */\n    function _setupDecimals(uint8 decimals_) internal {\n        _decimals = decimals_;\n    }\n\n    /**\n     * @dev Hook that is called before any transfer of tokens. This includes\n     * minting and burning.\n     *\n     * Calling conditions:\n     *\n     * - when `from` and `to` are both non-zero, `amount` of ``from``\u0027s tokens\n     * will be to transferred to `to`.\n     * - when `from` is zero, `amount` tokens will be minted for `to`.\n     * - when `to` is zero, `amount` of ``from``\u0027s tokens will be burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }\n}"},"IERC20.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/token/ERC20/IERC20.sol\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Returns the number of decimal places.\n     */\n    function decimals() external view returns (uint8);\n\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller\u0027s account to `recipient`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n}"},"IUniswapV2Pair.sol":{"content":"\npragma solidity ^0.6.12;\n\ninterface IUniswapV2Pair {\n    event Approval(address indexed owner, address indexed spender, uint value);\n    event Transfer(address indexed from, address indexed to, uint value);\n\n    function name() external pure returns (string memory);\n    function symbol() external pure returns (string memory);\n    function decimals() external pure returns (uint8);\n    function totalSupply() external view returns (uint);\n    function balanceOf(address owner) external view returns (uint);\n    function allowance(address owner, address spender) external view returns (uint);\n\n    function approve(address spender, uint value) external returns (bool);\n    function transfer(address to, uint value) external returns (bool);\n    function transferFrom(address from, address to, uint value) external returns (bool);\n\n    function DOMAIN_SEPARATOR() external view returns (bytes32);\n    function PERMIT_TYPEHASH() external pure returns (bytes32);\n    function nonces(address owner) external view returns (uint);\n\n    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;\n\n    event Mint(address indexed sender, uint amount0, uint amount1);\n    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);\n    event Swap(\n        address indexed sender,\n        uint amount0In,\n        uint amount1In,\n        uint amount0Out,\n        uint amount1Out,\n        address indexed to\n    );\n    event Sync(uint112 reserve0, uint112 reserve1);\n\n    function MINIMUM_LIQUIDITY() external pure returns (uint);\n    function factory() external view returns (address);\n    function token0() external view returns (address);\n    function token1() external view returns (address);\n    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);\n    function price0CumulativeLast() external view returns (uint);\n    function price1CumulativeLast() external view returns (uint);\n    function kLast() external view returns (uint);\n\n    function mint(address to) external returns (uint liquidity);\n    function burn(address to) external returns (uint amount0, uint amount1);\n    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;\n    function skim(address to) external;\n    function sync() external;\n\n    function initialize(address, address) external;\n}"},"IUniswapV2Router02.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol\n\ninterface IUniswapV2Router01 {\n    function factory() external pure returns (address);\n    function WETH() external pure returns (address);\n\n    function addLiquidity(\n        address tokenA,\n        address tokenB,\n        uint amountADesired,\n        uint amountBDesired,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountA, uint amountB, uint liquidity);\n    function addLiquidityETH(\n        address token,\n        uint amountTokenDesired,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);\n    function removeLiquidity(\n        address tokenA,\n        address tokenB,\n        uint liquidity,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountA, uint amountB);\n    function removeLiquidityETH(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountToken, uint amountETH);\n    function removeLiquidityWithPermit(\n        address tokenA,\n        address tokenB,\n        uint liquidity,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountA, uint amountB);\n    function removeLiquidityETHWithPermit(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountToken, uint amountETH);\n    function swapExactTokensForTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external returns (uint[] memory amounts);\n    function swapTokensForExactTokens(\n        uint amountOut,\n        uint amountInMax,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external returns (uint[] memory amounts);\n    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)\n        external\n        payable\n        returns (uint[] memory amounts);\n    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)\n        external\n        returns (uint[] memory amounts);\n    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)\n        external\n        returns (uint[] memory amounts);\n    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)\n        external\n        payable\n        returns (uint[] memory amounts);\n\n    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);\n    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);\n    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);\n    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);\n    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);\n}\n\ninterface IUniswapV2Router02 is IUniswapV2Router01 {\n    function removeLiquidityETHSupportingFeeOnTransferTokens(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountETH);\n    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountETH);\n\n    function swapExactTokensForTokensSupportingFeeOnTransferTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external;\n    function swapExactETHForTokensSupportingFeeOnTransferTokens(\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external payable;\n    function swapExactTokensForETHSupportingFeeOnTransferTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external;\n}"},"Ownable.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./Context.sol\u0027;\n\n// File: @openzeppelin/contracts/access/Ownable.sol\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\ncontract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor () internal {\n        address msgSender = _msgSender();\n        _owner = msgSender;\n        emit OwnershipTransferred(address(0), msgSender);\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        require(_owner == _msgSender(), \"Ownable: caller is not the owner\");\n        _;\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        emit OwnershipTransferred(_owner, address(0));\n        _owner = address(0);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        emit OwnershipTransferred(_owner, newOwner);\n        _owner = newOwner;\n    }\n}"},"SafeERC20.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./Address.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\n\n// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n    using SafeMath for uint256;\n    using Address for address;\n\n    function safeTransfer(IERC20 token, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n    }\n\n    /**\n     * @dev Deprecated. This function has issues similar to the ones found in\n     * {IERC20-approve}, and its usage is discouraged.\n     *\n     * Whenever possible, use {safeIncreaseAllowance} and\n     * {safeDecreaseAllowance} instead.\n     */\n    function safeApprove(IERC20 token, address spender, uint256 value) internal {\n        // safeApprove should only be called when setting an initial allowance,\n        // or when resetting it to zero. To increase and decrease it, use\n        // \u0027safeIncreaseAllowance\u0027 and \u0027safeDecreaseAllowance\u0027\n        // solhint-disable-next-line max-line-length\n        require((value == 0) || (token.allowance(address(this), spender) == 0),\n            \"SafeERC20: approve from non-zero to non-zero allowance\"\n        );\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n    }\n\n    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).add(value);\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).sub(value, \"SafeERC20: decreased allowance below zero\");\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     */\n    function _callOptionalReturn(IERC20 token, bytes memory data) private {\n        // We need to perform a low level call here, to bypass Solidity\u0027s return data size checking mechanism, since\n        // we\u0027re implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that\n        // the target address contains contract code and also asserts for success in the low-level call.\n\n        bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n        if (returndata.length \u003e 0) { // Return data is optional\n            // solhint-disable-next-line max-line-length\n            require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n        }\n    }\n}"},"SafeMath.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\n/**\n * @dev Wrappers over Solidity\u0027s arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it\u0027s recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c \u003e= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        return sub(a, b, \"SafeMath: subtraction overflow\");\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003c= a, errorMessage);\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\n        // benefit is lost if \u0027b\u0027 is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        return div(a, b, \"SafeMath: division by zero\");\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003e 0, errorMessage);\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn\u0027t hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        return mod(a, b, \"SafeMath: modulo by zero\");\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts with custom message when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b != 0, errorMessage);\n        return a % b;\n    }\n}"},"SURF.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./ERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./Whirlpool.sol\u0027;\n\ninterface Callable {\n    function tokenCallback(address _from, uint256 _tokens, bytes calldata _data) external returns (bool);\n    function receiveApproval(address _from, uint256 _tokens, address _token, bytes calldata _data) external;\n}\n\n// SURF Token with Governance. The governance contract will own the SURF, Tito, and Whirlpool contracts,\n// allowing SURF token holders to make and vote on proposals that can modify many parts of the protocol.\ncontract SURF is ERC20(\"SURF.Finance\", \"SURF\"), Ownable {\n\n    // There will be a max supply of 10,000,000 SURF tokens\n    uint256 public constant MAX_SUPPLY = 10000000 * 10**18;\n    bool public maxSupplyHit = false;\n\n    // The SURF transfer fee that gets rewarded to Whirlpool stakers (1 = 0.1%). Defaults to 1%\n    uint256 public transferFee = 10;\n\n    // Mapping of whitelisted sender and recipient addresses that don\u0027t pay the transfer fee. Allows SURF token holders to whitelist future contracts\n    mapping(address =\u003e bool) public senderWhitelist;\n    mapping(address =\u003e bool) public recipientWhitelist;\n\n    // The Tito contract\n    address public titoAddress;\n\n    // The Whirlpool contract\n    address payable public whirlpoolAddress;\n\n    // The Uniswap SURF-ETH LP token address\n    address public surfPoolAddress;\n\n    // Creates `_amount` token to `_to`. Can only be called by the Tito contract.\n    function mint(address _to, uint256 _amount) public {\n        require(maxSupplyHit != true, \"max supply hit\");\n        require(msg.sender == titoAddress, \"not Tito\");\n        uint256 supply = totalSupply();\n        if (supply.add(_amount) \u003e= MAX_SUPPLY) {\n            _amount = MAX_SUPPLY.sub(supply);\n            maxSupplyHit = true;\n        }\n\n        if (_amount \u003e 0) {\n            _mint(_to, _amount);\n            _moveDelegates(address(0), _delegates[_to], _amount);\n        }\n    }\n\n    // Sets the addresses of the Tito farming contract, the Whirlpool staking contract, and the Uniswap SURF-ETH LP token\n    function setContractAddresses(address _titoAddress, address payable _whirlpoolAddress, address _surfPoolAddress) public onlyOwner {\n        if (_titoAddress != address(0)) titoAddress = _titoAddress;\n        if (_whirlpoolAddress != address(0)) whirlpoolAddress = _whirlpoolAddress;\n        if (_surfPoolAddress != address(0)) surfPoolAddress = _surfPoolAddress;\n    }\n\n    // Sets the SURF transfer fee that gets rewarded to Whirlpool stakers. Can\u0027t be higher than 10%.\n    function setTransferFee(uint256 _transferFee) public onlyOwner {\n        require(_transferFee \u003c= 100, \"over 10%\");\n        transferFee = _transferFee;\n    }\n\n    // Add an address to the sender or recipient transfer whitelist\n    function addToTransferWhitelist(bool _addToSenderWhitelist, address _address) public onlyOwner {\n        if (_addToSenderWhitelist == true) senderWhitelist[_address] = true;\n        else recipientWhitelist[_address] = true;\n    }\n\n    // Remove an address from the sender or recipient transfer whitelist\n    function removeFromTransferWhitelist(bool _removeFromSenderWhitelist, address _address) public onlyOwner {\n        if (_removeFromSenderWhitelist == true) senderWhitelist[_address] = false;\n        else recipientWhitelist[_address] = false;\n    }\n\n    // Both the Tito and Whirlpool contracts will lock the SURF-ETH LP tokens they receive from their staking/unstaking fees here (ensuring liquidity forever).\n    // This function allows SURF token holders to decide what to do with the locked LP tokens in the future\n    function migrateLockedLPTokens(address _to, uint256 _amount) public onlyOwner {\n        IERC20 surfPool = IERC20(surfPoolAddress);\n        require(_amount \u003e 0 \u0026\u0026 _amount \u003c= surfPool.balanceOf(address(this)), \"bad amount\");\n        surfPool.transfer(_to, _amount);\n    }\n\n    function approveAndCall(address _spender, uint256 _tokens, bytes calldata _data) external returns (bool) {\n        approve(_spender, _tokens);\n        Callable(_spender).receiveApproval(msg.sender, _tokens, address(this), _data);\n        return true;\n    }\n\n    function transferAndCall(address _to, uint256 _tokens, bytes calldata _data) external returns (bool) {\n        uint256 _balanceBefore = balanceOf(_to);\n        transfer(_to, _tokens);\n        uint256 _tokensReceived = balanceOf(_to) - _balanceBefore;\n        uint32 _size;\n        assembly {\n            _size := extcodesize(_to)\n        }\n        if (_size \u003e 0) {\n            require(Callable(_to).tokenCallback(msg.sender, _tokensReceived, _data));\n        }\n        return true;\n    }\n\n    // There\u0027s a fee on every SURF transfer that gets sent to the Whirlpool staking contract which will start getting rewarded to stakers after the max supply is hit.\n    // The transfer fee will reduce the front-running of Uniswap trades and will provide a major incentive to hold and stake SURF long-term.\n    // Transfers to/from the Tito or Whirlpool contracts will not pay a fee.\n    function _transfer(address sender, address recipient, uint256 amount) internal override {\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        uint256 transferFeeAmount;\n        uint256 tokensToTransfer;\n\n        if (amount \u003e 0) {\n\n            // Send a fee to the Whirlpool staking contract if this isn\u0027t a whitelisted transfer\n            if (_isWhitelistedTransfer(sender, recipient) != true) {\n                transferFeeAmount = amount.mul(transferFee).div(1000);\n                _balances[whirlpoolAddress] = _balances[whirlpoolAddress].add(transferFeeAmount);\n                _moveDelegates(_delegates[sender], _delegates[whirlpoolAddress], transferFeeAmount);\n                Whirlpool(whirlpoolAddress).addSurfReward(sender, transferFeeAmount);\n                emit Transfer(sender, whirlpoolAddress, transferFeeAmount);\n            }\n\n            tokensToTransfer = amount.sub(transferFeeAmount);\n\n            _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n\n            if (tokensToTransfer \u003e 0) {\n                _balances[recipient] = _balances[recipient].add(tokensToTransfer);\n                _moveDelegates(_delegates[sender], _delegates[recipient], tokensToTransfer);\n\n                // If the Whirlpool staking contract is the transfer recipient, addSurfReward gets called to keep things in sync\n                if (recipient == whirlpoolAddress) Whirlpool(whirlpoolAddress).addSurfReward(sender, tokensToTransfer);\n            }\n\n        }\n\n        emit Transfer(sender, recipient, tokensToTransfer);\n    }\n\n    // Internal function to determine if a SURF transfer is being sent or received by a whitelisted address\n    function _isWhitelistedTransfer(address _sender, address _recipient) internal view returns (bool) {\n        // The Whirlpool and Tito contracts are always whitelisted\n        return\n            _sender == whirlpoolAddress || _recipient == whirlpoolAddress ||\n            _sender == titoAddress || _recipient == titoAddress ||\n            senderWhitelist[_sender] == true || recipientWhitelist[_recipient] == true;\n    }\n\n    // Copied and modified from YAM code:\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol\n    // Which is copied and modified from COMPOUND:\n    // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol\n\n    /// @dev A record of each accounts delegate\n    mapping (address =\u003e address) internal _delegates;\n\n    /// @dev A checkpoint for marking number of votes from a given block\n    struct Checkpoint {\n        uint32 fromBlock;\n        uint256 votes;\n    }\n\n    /// @dev A record of votes checkpoints for each account, by index\n    mapping (address =\u003e mapping (uint32 =\u003e Checkpoint)) public checkpoints;\n\n    /// @dev The number of checkpoints for each account\n    mapping (address =\u003e uint32) public numCheckpoints;\n\n    /// @dev The EIP-712 typehash for the contract\u0027s domain\n    bytes32 public constant DOMAIN_TYPEHASH = keccak256(\"EIP712Domain(string name,uint256 chainId,address verifyingContract)\");\n\n    /// @dev The EIP-712 typehash for the delegation struct used by the contract\n    bytes32 public constant DELEGATION_TYPEHASH = keccak256(\"Delegation(address delegatee,uint256 nonce,uint256 expiry)\");\n\n    /// @dev A record of states for signing / validating signatures\n    mapping (address =\u003e uint) public nonces;\n\n      /// @dev An event thats emitted when an account changes its delegate\n    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);\n\n    /// @dev An event thats emitted when a delegate account\u0027s vote balance changes\n    event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);\n\n    /**\n     * @dev Delegate votes from `msg.sender` to `delegatee`\n     * @param delegator The address to get delegatee for\n     */\n    function delegates(address delegator) external view returns (address) {\n        return _delegates[delegator];\n    }\n\n   /**\n    * @dev Delegate votes from `msg.sender` to `delegatee`\n    * @param delegatee The address to delegate votes to\n    */\n    function delegate(address delegatee) external {\n        return _delegate(msg.sender, delegatee);\n    }\n\n    /**\n     * @dev Delegates votes from signatory to `delegatee`\n     * @param delegatee The address to delegate votes to\n     * @param nonce The contract state required to match the signature\n     * @param expiry The time at which to expire the signature\n     * @param v The recovery byte of the signature\n     * @param r Half of the ECDSA signature pair\n     * @param s Half of the ECDSA signature pair\n     */\n    function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) external {\n        bytes32 domainSeparator = keccak256(\n            abi.encode(\n                DOMAIN_TYPEHASH,\n                keccak256(bytes(name())),\n                getChainId(),\n                address(this)\n            )\n        );\n\n        bytes32 structHash = keccak256(\n            abi.encode(\n                DELEGATION_TYPEHASH,\n                delegatee,\n                nonce,\n                expiry\n            )\n        );\n\n        bytes32 digest = keccak256(\n            abi.encodePacked(\n                \"\\x19\\x01\",\n                domainSeparator,\n                structHash\n            )\n        );\n\n        address signatory = ecrecover(digest, v, r, s);\n        require(signatory != address(0), \"SURF::delegateBySig: invalid signature\");\n        require(nonce == nonces[signatory]++, \"SURF::delegateBySig: invalid nonce\");\n        require(now \u003c= expiry, \"SURF::delegateBySig: signature expired\");\n        return _delegate(signatory, delegatee);\n    }\n\n    /**\n     * @dev Gets the current votes balance for `account`\n     * @param account The address to get votes balance\n     * @return The number of current votes for `account`\n     */\n    function getCurrentVotes(address account) external view returns (uint256) {\n        uint32 nCheckpoints = numCheckpoints[account];\n        return nCheckpoints \u003e 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;\n    }\n\n    /**\n     * @dev Determine the prior number of votes for an account as of a block number\n     * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.\n     * @param account The address of the account to check\n     * @param blockNumber The block number to get the vote balance at\n     * @return The number of votes the account had as of the given block\n     */\n    function getPriorVotes(address account, uint blockNumber) external view returns (uint256) {\n        require(blockNumber \u003c block.number, \"SURF::getPriorVotes: not yet determined\");\n\n        uint32 nCheckpoints = numCheckpoints[account];\n        if (nCheckpoints == 0) {\n            return 0;\n        }\n\n        // First check most recent balance\n        if (checkpoints[account][nCheckpoints - 1].fromBlock \u003c= blockNumber) {\n            return checkpoints[account][nCheckpoints - 1].votes;\n        }\n\n        // Next check implicit zero balance\n        if (checkpoints[account][0].fromBlock \u003e blockNumber) {\n            return 0;\n        }\n\n        uint32 lower = 0;\n        uint32 upper = nCheckpoints - 1;\n        while (upper \u003e lower) {\n            uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow\n            Checkpoint memory cp = checkpoints[account][center];\n            if (cp.fromBlock == blockNumber) {\n                return cp.votes;\n            } else if (cp.fromBlock \u003c blockNumber) {\n                lower = center;\n            } else {\n                upper = center - 1;\n            }\n        }\n        return checkpoints[account][lower].votes;\n    }\n\n    function _delegate(address delegator, address delegatee) internal {\n        address currentDelegate = _delegates[delegator];\n        uint256 delegatorBalance = balanceOf(delegator); // balance of underlying SURFs (not scaled);\n        _delegates[delegator] = delegatee;\n\n        emit DelegateChanged(delegator, currentDelegate, delegatee);\n\n        _moveDelegates(currentDelegate, delegatee, delegatorBalance);\n    }\n\n    function _moveDelegates(address srcRep, address dstRep, uint256 amount) internal {\n        if (srcRep != dstRep \u0026\u0026 amount \u003e 0) {\n            if (srcRep != address(0)) {\n                // decrease old representative\n                uint32 srcRepNum = numCheckpoints[srcRep];\n                uint256 srcRepOld = srcRepNum \u003e 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;\n                uint256 srcRepNew = srcRepOld.sub(amount);\n                _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);\n            }\n\n            if (dstRep != address(0)) {\n                // increase new representative\n                uint32 dstRepNum = numCheckpoints[dstRep];\n                uint256 dstRepOld = dstRepNum \u003e 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;\n                uint256 dstRepNew = dstRepOld.add(amount);\n                _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);\n            }\n        }\n    }\n\n    function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint256 oldVotes, uint256 newVotes) internal {\n        uint32 blockNumber = safe32(block.number, \"SURF::_writeCheckpoint: block number exceeds 32 bits\");\n\n        if (nCheckpoints \u003e 0 \u0026\u0026 checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {\n            checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;\n        } else {\n            checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);\n            numCheckpoints[delegatee] = nCheckpoints + 1;\n        }\n\n        emit DelegateVotesChanged(delegatee, oldVotes, newVotes);\n    }\n\n    function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {\n        require(n \u003c 2**32, errorMessage);\n        return uint32(n);\n    }\n\n    function getChainId() internal pure returns (uint) {\n        uint256 chainId;\n        assembly { chainId := chainid() }\n        return chainId;\n    }\n}"},"Tito.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./SafeERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./IUniswapV2Router02.sol\u0027;\nimport \u0027./UniStakingInterfaces.sol\u0027;\nimport \u0027./SURF.sol\u0027;\nimport \u0027./Whirlpool.sol\u0027;\n\n// Tito is the master of SURF. He can make SURF, is a fair guy, and a great instructor.\ncontract Tito is Ownable {\n    using SafeMath for uint256;\n    using SafeERC20 for IERC20;\n\n    // Info of each user.\n    struct UserInfo {\n        uint256 staked; // How many LP tokens the user has provided.\n        uint256 rewardDebt; // Reward debt. See explanation below.\n        uint256 uniRewardDebt; // UNI staking reward debt. See explanation below.\n        uint256 claimed; // Tracks the amount of SURF claimed by the user.\n        uint256 uniClaimed; // Tracks the amount of UNI claimed by the user.\n    }\n\n    // Info of each pool.\n    struct PoolInfo {\n        IERC20 token; // Address of token contract.\n        IERC20 lpToken; // Address of LP token contract.\n        uint256 apr; // Fixed APR for the pool. Determines how many SURFs to distribute per block.\n        uint256 lastSurfRewardBlock; // Last block number that SURF rewards were distributed.\n        uint256 accSurfPerShare; // Accumulated SURFs per share, times 1e12. See below.\n        uint256 accUniPerShare; // Accumulated UNIs per share, times 1e12. See below.\n        address uniStakeContract; // Address of UNI staking contract (if applicable).\n    }\n\n    // We do some fancy math here. Basically, any point in time, the amount of SURFs\n    // entitled to a user but is pending to be distributed is:\n    //\n    //   pending reward = (user.staked * pool.accSurfPerShare) - user.rewardDebt\n    //\n    // Whenever a user deposits or withdraws LP tokens to a pool. Here\u0027s what happens:\n    //   1. The pool\u0027s `accSurfPerShare` (and `lastSurfRewardBlock`) gets updated.\n    //   2. User receives the pending reward sent to his/her address.\n    //   3. User\u0027s `staked` amount gets updated.\n    //   4. User\u0027s `rewardDebt` gets updated.\n\n    // The SURF TOKEN!\n    SURF public surf;\n    // The address of the SURF-ETH Uniswap pool\n    address public surfPoolAddress;\n     // The Whirlpool staking contract\n    Whirlpool public whirlpool;\n    // The Uniswap v2 Router\n    IUniswapV2Router02 internal uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);\n    // The UNI Staking Rewards Factory\n    StakingRewardsFactory internal uniStakingFactory = StakingRewardsFactory(0x3032Ab3Fa8C01d786D29dAdE018d7f2017918e12);\n    // The UNI Token\n    IERC20 internal uniToken = IERC20(0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984);\n    // The WETH Token\n    IERC20 internal weth;\n    // Dev address\n    address payable public devAddress;\n\n    // Info of each pool.\n    PoolInfo[] public poolInfo;\n    mapping(address =\u003e bool) public existingPools;\n    // Info of each user that stakes LP tokens.\n    mapping (uint256 =\u003e mapping (address =\u003e UserInfo)) public userInfo;\n    // Mapping of whitelisted contracts so that certain contracts like the Aegis pool can interact with the Tito contract\n    mapping(address =\u003e bool) public contractWhitelist;\n    // The block number when SURF mining starts.\n    uint256 public startBlock;\n    // Becomes true once the SURF-ETH Uniswap is created (no sooner than 500 blocks after launch)\n    bool public surfPoolActive = false;\n    // The staking fees collected during the first 500 blocks will seed the SURF-ETH Uniswap pool\n    uint256 public initialSurfPoolETH  = 0;\n    // 5% of every deposit into any secondary pool (not SURF-ETH) will be converted to SURF (on Uniswap) and sent to the Whirlpool staking contract which becomes active and starts distributing the accumulated SURF to stakers once the max supply is hit\n    uint256 public surfSentToWhirlpool = 0;\n    // The amount of ETH donated to the SURF community by partner projects\n    uint256 public donatedETH = 0;\n    // Certain partner projects need to donate 25 ETH to the SURF community to get a beach\n    uint256 public minimumDonationAmount = 25 * 10**18;\n    // Mapping of addresses that donated ETH on behalf of a partner project\n    mapping(address =\u003e address) public donaters;\n    // Mapping of the size of donations from partner projects\n    mapping(address =\u003e uint256) public donations;\n    // Approximate number of blocks per year - assumes 13 second blocks\n    uint256 internal constant APPROX_BLOCKS_PER_YEAR  = uint256(uint256(365 days) / uint256(13 seconds));\n    // The default APR for each pool will be 1,000%\n    uint256 internal constant DEFAULT_APR = 1000;\n    // There will be a 1000 block Soft Launch in which SURF is minted to each pool at a static rate to make the start as fair as possible\n    uint256 internal constant SOFT_LAUNCH_DURATION = 1000;\n    // During the Soft Launch, all pools except for the SURF-ETH pool will mint 40 SURF per block. Once it\u0027s activated, the SURF-ETH pool will mint the same amount of SURF per block as all of the other pools combined until the end of the Soft Launch\n    uint256 internal constant SOFT_LAUNCH_SURF_PER_BLOCK = 40 * 10**18;\n\n    event Deposit(address indexed user, uint256 indexed pid, uint256 amount);\n    event Claim(address indexed user, uint256 indexed pid, uint256 surfAmount, uint256 uniAmount);\n    event ClaimAll(address indexed user, uint256 surfAmount, uint256 uniAmount);\n    event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);\n    event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);\n    event SurfBuyback(address indexed user, uint256 ethSpentOnSurf, uint256 surfBought);\n    event SurfPoolActive(address indexed user, uint256 surfLiquidity, uint256 ethLiquidity);\n\n    constructor(\n        SURF _surf,\n        address payable _devAddress,\n        uint256 _startBlock\n    ) public {\n        surf = _surf;\n        devAddress = _devAddress;\n        startBlock = _startBlock;\n        weth = IERC20(uniswapRouter.WETH());\n\n        // Calculate the address the SURF-ETH Uniswap pool will exist at\n        address uniswapfactoryAddress = uniswapRouter.factory();\n        address surfAddress = address(surf);\n        address wethAddress = address(weth);\n\n        // token0 must be strictly less than token1 by sort order to determine the correct address\n        (address token0, address token1) = surfAddress \u003c wethAddress ? (surfAddress, wethAddress) : (wethAddress, surfAddress);\n\n        surfPoolAddress = address(uint(keccak256(abi.encodePacked(\n            hex\u0027ff\u0027,\n            uniswapfactoryAddress,\n            keccak256(abi.encodePacked(token0, token1)),\n            hex\u002796e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f\u0027\n        ))));\n\n        _addInitialPools();\n    }\n\n    receive() external payable {}\n\n    // Internal function to add a new LP Token pool\n    function _addPool(address _token, address _lpToken) internal {\n\n        uint256 apr = DEFAULT_APR;\n        if (_token == address(surf)) apr = apr * 5;\n\n        uint256 lastSurfRewardBlock = block.number \u003e startBlock ? block.number : startBlock;\n\n        poolInfo.push(\n            PoolInfo({\n                token: IERC20(_token),\n                lpToken: IERC20(_lpToken),\n                apr: apr,\n                lastSurfRewardBlock: lastSurfRewardBlock,\n                accSurfPerShare: 0,\n                accUniPerShare: 0,\n                uniStakeContract: address(0)\n            })\n        );\n\n        existingPools[_lpToken] = true;\n    }\n\n    // Internal function that adds all of the pools that will be available at launch. Called by the constructor\n    function _addInitialPools() internal {\n\n        _addPool(address(surf), surfPoolAddress); // SURF-ETH\n\n        _addPool(0xdAC17F958D2ee523a2206206994597C13D831ec7, 0x0d4a11d5EEaaC28EC3F61d100daF4d40471f1852); // ETH-USDT\n        _addPool(0x6B175474E89094C44Da98b954EedeAC495271d0F, 0xA478c2975Ab1Ea89e8196811F51A7B7Ade33eB11); // DAI-ETH\n        _addPool(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, 0xB4e16d0168e52d35CaCD2c6185b44281Ec28C9Dc); // USDC-ETH\n        _addPool(0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599, 0xBb2b8038a1640196FbE3e38816F3e67Cba72D940); // WBTC-ETH\n        _addPool(0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, 0xd3d2E2692501A5c9Ca623199D38826e513033a17); // UNI-ETH\n        _addPool(0x514910771AF9Ca656af840dff83E8264EcF986CA, 0xa2107FA5B38d9bbd2C461D6EDf11B11A50F6b974); // LINK-ETH\n        _addPool(0x7Fc66500c84A76Ad7e9c93437bFc5Ac33E2DDaE9, 0xDFC14d2Af169B0D36C4EFF567Ada9b2E0CAE044f); // AAVE-ETH\n        _addPool(0xC011a73ee8576Fb46F5E1c5751cA3B9Fe0af2a6F, 0x43AE24960e5534731Fc831386c07755A2dc33D47); // SNX-ETH\n        _addPool(0x9f8F72aA9304c8B593d555F12eF6589cC3A579A2, 0xC2aDdA861F89bBB333c90c492cB837741916A225); // MKR-ETH\n        _addPool(0xc00e94Cb662C3520282E6f5717214004A7f26888, 0xCFfDdeD873554F362Ac02f8Fb1f02E5ada10516f); // COMP-ETH\n        _addPool(0x0bc529c00C6401aEF6D220BE8C6Ea1667F6Ad93e, 0x2fDbAdf3C4D5A8666Bc06645B8358ab803996E28); // YFI-ETH\n        _addPool(0xba100000625a3754423978a60c9317c58a424e3D, 0xA70d458A4d9Bc0e6571565faee18a48dA5c0D593); // BAL-ETH\n        _addPool(0x1494CA1F11D487c2bBe4543E90080AeBa4BA3C2b, 0x4d5ef58aAc27d99935E5b6B4A6778ff292059991); // DPI-ETH\n        _addPool(0xD46bA6D942050d489DBd938a2C909A5d5039A161, 0xc5be99A02C6857f9Eac67BbCE58DF5572498F40c); // AMPL-ETH\n        _addPool(0x2b591e99afE9f32eAA6214f7B7629768c40Eeb39, 0x55D5c232D921B9eAA6b37b5845E439aCD04b4DBa); // HEX-ETH\n        _addPool(0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d, 0x343FD171caf4F0287aE6b87D75A8964Dc44516Ab); // PNK-ETH\n        _addPool(0x429881672B9AE42b8EbA0E26cD9C73711b891Ca5, 0xdc98556Ce24f007A5eF6dC1CE96322d65832A819); // PICKLE-ETH\n        _addPool(0x84294FC9710e1252d407d3D80A84bC39001bd4A8, 0x0C5136B5d184379fa15bcA330784f2d5c226Fe96); // NUTS-ETH\n        _addPool(0x821144518dfE9e7b44fCF4d0824e15e8390d4637, 0x490B5B2489eeFC4106C69743F657e3c4A2870aC5); // ATIS-ETH\n        _addPool(0xB9464ef80880c5aeA54C7324c0b8Dd6ca6d05A90, 0xa8D0f6769AB020877f262D8Cd747c188D9097d7E); // LOCK-ETH\n        _addPool(0x926dbD499d701C61eABe2d576e770ECCF9c7F4F3, 0xC7c0EDf0b5f89eff96aF0E31643Bd588ad63Ea23); // aDAO-ETH\n        _addPool(0x3A9FfF453d50D4Ac52A6890647b823379ba36B9E, 0x260E069deAd76baAC587B5141bB606Ef8b9Bab6c); // SHUF-ETH\n        _addPool(0x9720Bcf5a92542D4e286792fc978B63a09731CF0, 0x08538213596fB2c392e9c5d4935ad37645600a57); // OTBC-ETH\n        _addPool(0xEEF9f339514298C6A857EfCfC1A762aF84438dEE, 0x23d15EDceb5B5B3A23347Fa425846DE80a2E8e5C); // HEZ-ETH\n\n        // These beaches will be manually added after their teams make the 25 ETH donation\n        // _addPool(0x6F87D756DAf0503d08Eb8993686c7Fc01Dc44fB1, 0xd2E0C4928789e5DB620e53af29F5fC7bcA262635); // TRADE-ETH\n        \n    }\n\n    // Get the pending SURFs for a user from 1 pool\n    function _pendingSurf(uint256 _pid, address _user) internal view returns (uint256) {\n        if (_pid == 0 \u0026\u0026 surfPoolActive != true) return 0;\n\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo memory user = userInfo[_pid][_user];\n        uint256 accSurfPerShare = pool.accSurfPerShare;\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        if (block.number \u003e pool.lastSurfRewardBlock \u0026\u0026 lpSupply != 0) {\n            uint256 surfReward = _calculateSurfReward(_pid, lpSupply);\n\n            // Make sure that surfReward won\u0027t push the total supply of SURF past surf.MAX_SUPPLY()\n            uint256 surfTotalSupply = surf.totalSupply();\n            if (surfTotalSupply.add(surfReward) \u003e= surf.MAX_SUPPLY()) {\n                surfReward = surf.MAX_SUPPLY().sub(surfTotalSupply);\n            }\n\n            accSurfPerShare = accSurfPerShare.add(surfReward.mul(1e12).div(lpSupply));\n        }\n\n        return user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n    }\n\n    // Get the pending UNIs for a user from 1 pool\n    function _pendingUni(uint256 _pid, address _user) internal view returns (uint256) {\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo memory user = userInfo[_pid][_user];\n        uint256 accUniPerShare = pool.accUniPerShare;\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        if (pool.uniStakeContract != address(0) \u0026\u0026 lpSupply != 0) {\n            uint256 uniReward = IStakingRewards(pool.uniStakeContract).earned(address(this));\n            accUniPerShare = accUniPerShare.add(uniReward.mul(1e12).div(lpSupply));\n        }\n        return user.staked.mul(accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n    }\n\n    // Calculate the current surfReward for a specific pool\n    function _calculateSurfReward(uint256 _pid, uint256 _lpSupply) internal view returns (uint256 surfReward) {\n        \n        if (surf.maxSupplyHit() != true) {\n\n            PoolInfo memory pool = poolInfo[_pid];\n\n            uint256 multiplier = block.number - pool.lastSurfRewardBlock;\n                \n            // There will be a 1000 block Soft Launch where SURF is minted at a static rate to make things as fair as possible\n            if (block.number \u003c startBlock + SOFT_LAUNCH_DURATION) {\n\n                // The SURF-ETH pool isn\u0027t active until the Uniswap pool is created, which can\u0027t happen until at least 500 blocks have passed. Once active, it mints 1000 SURF per block (the same amount of SURF per block as all of the other pools combined) until the Soft Launch ends\n                if (_pid != 0) {\n                    // For the first 1000 blocks, give 40 SURF per block to all other pools that have staked LP tokens\n                    surfReward = multiplier * SOFT_LAUNCH_SURF_PER_BLOCK;\n                } else if (surfPoolActive == true) {\n                    surfReward = multiplier * 25 * SOFT_LAUNCH_SURF_PER_BLOCK;\n                }\n            \n            } else if (_pid != 0 \u0026\u0026 surfPoolActive != true) {\n                // Keep minting 40 tokens per block since the Soft Launch is over but the SURF-ETH pool still isn\u0027t active (would only be due to no one calling the activateSurfPool function)\n                surfReward = multiplier * SOFT_LAUNCH_SURF_PER_BLOCK;\n            } else if (surfPoolActive == true) { \n                // Afterwards, give surfReward based on the pool\u0027s fixed APR.\n                // Fast low gas cost way of calculating prices since this can be called every block.\n                uint256 surfPrice = _getSurfPrice();\n                uint256 lpTokenPrice = 10**18 * 2 * weth.balanceOf(address(pool.lpToken)) / pool.lpToken.totalSupply(); \n                uint256 scaledTotalLiquidityValue = _lpSupply * lpTokenPrice;\n                surfReward = multiplier * ((pool.apr * scaledTotalLiquidityValue / surfPrice) / APPROX_BLOCKS_PER_YEAR) / 100;\n            }\n\n        }\n\n    }\n\n    function poolLength() external view returns (uint256) {\n        return poolInfo.length;\n    }\n\n    // Internal view function to get all of the stored data for a single pool\n    function _getPoolData(uint256 _pid) internal view returns (address, address, bool, uint256, uint256, uint256, uint256) {\n        PoolInfo memory pool = poolInfo[_pid];\n        return (address(pool.token), address(pool.lpToken), pool.uniStakeContract != address(0), pool.apr, pool.lastSurfRewardBlock, pool.accSurfPerShare, pool.accUniPerShare);\n    }\n\n    // View function to see all of the stored data for every pool on the frontend\n    function _getAllPoolData() internal view returns (address[] memory, address[] memory, bool[] memory, uint[] memory, uint[] memory, uint[2][] memory) {\n        uint256 length = poolInfo.length;\n        address[] memory tokenData = new address[](length);\n        address[] memory lpTokenData = new address[](length);\n        bool[] memory isUniData = new bool[](length);\n        uint[] memory aprData = new uint[](length);\n        uint[] memory lastSurfRewardBlockData = new uint[](length);\n        uint[2][] memory accTokensPerShareData = new uint[2][](length);\n\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            (tokenData[pid], lpTokenData[pid], isUniData[pid], aprData[pid], lastSurfRewardBlockData[pid], accTokensPerShareData[pid][0], accTokensPerShareData[pid][1]) = _getPoolData(pid);\n        }\n\n        return (tokenData, lpTokenData, isUniData, aprData, lastSurfRewardBlockData, accTokensPerShareData);\n    }\n\n    // Internal view function to get all of the extra data for a single pool\n    function _getPoolMetadataFor(uint256 _pid, address _user, uint256 _surfPrice) internal view returns (uint[17] memory poolMetadata) {\n        PoolInfo memory pool = poolInfo[_pid];\n\n        uint256 totalSupply;\n        uint256 totalLPSupply;\n        uint256 stakedLPSupply;\n        uint256 tokenPrice;\n        uint256 lpTokenPrice;\n        uint256 totalLiquidityValue;\n        uint256 surfPerBlock;\n\n        if (_pid != 0 || surfPoolActive == true) {\n            totalSupply = pool.token.totalSupply();\n            totalLPSupply = pool.lpToken.totalSupply();\n            stakedLPSupply = _getPoolSupply(_pid);\n\n            tokenPrice = 10**uint256(pool.token.decimals()) * weth.balanceOf(address(pool.lpToken)) / pool.token.balanceOf(address(pool.lpToken));\n            lpTokenPrice = 10**18 * 2 * weth.balanceOf(address(pool.lpToken)) / totalLPSupply; \n            totalLiquidityValue = stakedLPSupply * lpTokenPrice / 1e18;\n        }\n\n        // Only calculate with fixed apr after the Soft Launch\n        if (block.number \u003e= startBlock + SOFT_LAUNCH_DURATION) {\n            surfPerBlock = ((pool.apr * 1e18 * totalLiquidityValue / _surfPrice) / APPROX_BLOCKS_PER_YEAR) / 100;\n        } else {\n            if (_pid != 0) {\n                surfPerBlock = SOFT_LAUNCH_SURF_PER_BLOCK;\n            } else if (surfPoolActive == true) {\n                surfPerBlock = 25 * SOFT_LAUNCH_SURF_PER_BLOCK;\n            }\n        }\n\n        // Global pool information\n        poolMetadata[0] = totalSupply;\n        poolMetadata[1] = totalLPSupply;\n        poolMetadata[2] = stakedLPSupply;\n        poolMetadata[3] = tokenPrice;\n        poolMetadata[4] = lpTokenPrice;\n        poolMetadata[5] = totalLiquidityValue;\n        poolMetadata[6] = surfPerBlock;\n        poolMetadata[7] = pool.token.decimals();\n\n        // User pool information\n        if (_pid != 0 || surfPoolActive == true) {\n            UserInfo memory _userInfo = userInfo[_pid][_user];\n            poolMetadata[8] = pool.token.balanceOf(_user);\n            poolMetadata[9] = pool.token.allowance(_user, address(this));\n            poolMetadata[10] = pool.lpToken.balanceOf(_user);\n            poolMetadata[11] = pool.lpToken.allowance(_user, address(this));\n            poolMetadata[12] = _userInfo.staked;\n            poolMetadata[13] = _pendingSurf(_pid, _user);\n            poolMetadata[14] = _pendingUni(_pid, _user);\n            poolMetadata[15] = _userInfo.claimed;\n            poolMetadata[16] = _userInfo.uniClaimed;\n        }\n    }\n\n    // View function to see all of the extra pool data (token prices, total staked supply, total liquidity value, etc) on the frontend\n    function _getAllPoolMetadataFor(address _user) internal view returns (uint[17][] memory allMetadata) {\n        uint256 length = poolInfo.length;\n\n        // Extra data for the frontend\n        allMetadata = new uint[17][](length);\n\n        // We\u0027ll need the current SURF price to make our calculations\n        uint256 surfPrice = _getSurfPrice();\n\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            allMetadata[pid] = _getPoolMetadataFor(pid, _user, surfPrice);\n        }\n    }\n\n    // View function to see all of the data for all pools on the frontend\n    function getAllPoolInfoFor(address _user) external view returns (address[] memory tokens, address[] memory lpTokens, bool[] memory isUnis, uint[] memory aprs, uint[] memory lastSurfRewardBlocks, uint[2][] memory accTokensPerShares, uint[17][] memory metadatas) {\n        (tokens, lpTokens, isUnis, aprs, lastSurfRewardBlocks, accTokensPerShares) = _getAllPoolData();\n        metadatas = _getAllPoolMetadataFor(_user);\n    }\n\n    // Internal view function to get the current price of SURF on Uniswap\n    function _getSurfPrice() internal view returns (uint256 surfPrice) {\n        uint256 surfBalance = surf.balanceOf(surfPoolAddress);\n        if (surfBalance \u003e 0) {\n            surfPrice = 10**18 * weth.balanceOf(surfPoolAddress) / surfBalance;\n        }\n    }\n\n    // View function to show all relevant platform info on the frontend\n    function getAllInfoFor(address _user) external view returns (bool poolActive, uint256[8] memory info) {\n        poolActive = surfPoolActive;\n        info[0] = blocksUntilLaunch();\n        info[1] = blocksUntilSurfPoolCanBeActivated();\n        info[2] = blocksUntilSoftLaunchEnds();\n        info[3] = surf.totalSupply();\n        info[4] = _getSurfPrice();\n        if (surfPoolActive) {\n            info[5] = IERC20(surfPoolAddress).balanceOf(address(surf));\n        }\n        info[6] = surfSentToWhirlpool;\n        info[7] = surf.balanceOf(_user);\n    }\n\n    // View function to see the number of blocks remaining until launch on the frontend\n    function blocksUntilLaunch() public view returns (uint256) {\n        if (block.number \u003e= startBlock) return 0;\n        else return startBlock.sub(block.number);\n    }\n\n    // View function to see the number of blocks remaining until the SURF pool can be activated on the frontend\n    function blocksUntilSurfPoolCanBeActivated() public view returns (uint256) {\n        uint256 surfPoolActivationBlock = startBlock + SOFT_LAUNCH_DURATION.div(2);\n        if (block.number \u003e= surfPoolActivationBlock) return 0;\n        else return surfPoolActivationBlock.sub(block.number);\n    }\n\n    // View function to see the number of blocks remaining until the Soft Launch ends on the frontend\n    function blocksUntilSoftLaunchEnds() public view returns (uint256) {\n        uint256 softLaunchEndBlock = startBlock + SOFT_LAUNCH_DURATION;\n        if (block.number \u003e= softLaunchEndBlock) return 0;\n        else return softLaunchEndBlock.sub(block.number);\n    }\n\n    // Update reward variables for all pools. Be careful of gas spending!\n    function massUpdatePools() public {\n        uint256 length = poolInfo.length;\n        for (uint256 pid = (surfPoolActive == true ? 0 : 1); pid \u003c length; ++pid) {\n            updatePool(pid);\n        }\n    }\n\n    // Update reward variables of the given pool to be up-to-date.\n    function updatePool(uint256 _pid) public {\n        require(msg.sender == tx.origin || msg.sender == owner() || contractWhitelist[msg.sender] == true, \"no contracts\"); // Prevent flash loan attacks that manipulate prices.\n        \n        PoolInfo storage pool = poolInfo[_pid];\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        // Handle the UNI staking rewards contract for the LP token if one exists.\n        // The SURF-ETH pool would break by using the UNI staking rewards contract if one is made for it so it will be ignored\n        if (_pid != 0) {\n            // Check to see if the LP token has a UNI staking rewards contract to forward deposits to so that users can earn both SURF and UNI\n            if (pool.uniStakeContract == address(0)) {\n                (address uniStakeContract,) = uniStakingFactory.stakingRewardsInfoByStakingToken(address(pool.lpToken));\n\n                // If a UNI staking rewards contract exists then transfer all of the LP tokens to it to start earning UNI\n                if (uniStakeContract != address(0)) {\n                    pool.uniStakeContract = uniStakeContract;\n\n                    if (lpSupply \u003e 0) {\n                        pool.lpToken.safeApprove(uniStakeContract, 0);\n                        pool.lpToken.approve(uniStakeContract, lpSupply);\n                        IStakingRewards(pool.uniStakeContract).stake(lpSupply);\n                    }\n                }\n            }\n\n            // A UNI staking rewards contract for this LP token is being used so get any pending UNI rewards\n            if (pool.uniStakeContract != address(0)) {\n                uint256 pendingUniTokens = IStakingRewards(pool.uniStakeContract).earned(address(this));\n                if (pendingUniTokens \u003e 0) {\n                    uint256 uniBalanceBefore = uniToken.balanceOf(address(this));\n                    IStakingRewards(pool.uniStakeContract).getReward();\n                    uint256 uniBalanceAfter = uniToken.balanceOf(address(this));\n                    pendingUniTokens = uniBalanceAfter.sub(uniBalanceBefore);\n                    pool.accUniPerShare = pool.accUniPerShare.add(pendingUniTokens.mul(1e12).div(lpSupply));\n                }\n            }\n        }\n\n        // Only update the pool if the max SURF supply hasn\u0027t been hit\n        if (surf.maxSupplyHit() != true) {\n            \n            if ((block.number \u003c= pool.lastSurfRewardBlock) || (_pid == 0 \u0026\u0026 surfPoolActive != true)) {\n                return;\n            }\n            if (lpSupply == 0) {\n                pool.lastSurfRewardBlock = block.number;\n                return;\n            }\n\n            uint256 surfReward = _calculateSurfReward(_pid, lpSupply);\n\n            // Make sure that surfReward won\u0027t push the total supply of SURF past surf.MAX_SUPPLY()\n            uint256 surfTotalSupply = surf.totalSupply();\n            if (surfTotalSupply.add(surfReward) \u003e= surf.MAX_SUPPLY()) {\n                surfReward = surf.MAX_SUPPLY().sub(surfTotalSupply);\n            }\n\n            // surf.mint(devAddress, surfReward.div(10)); Not minting 10% to the devs like Sushi, Sashimi, and Takeout do\n\n            if (surfReward \u003e 0) {\n                surf.mint(address(this), surfReward);\n                pool.accSurfPerShare = pool.accSurfPerShare.add(surfReward.mul(1e12).div(lpSupply));\n                pool.lastSurfRewardBlock = block.number;\n            }\n\n            if (surf.maxSupplyHit() == true) {\n                whirlpool.activate();\n            }\n        }\n    }\n\n    // Internal view function to get the amount of LP tokens staked in the specified pool\n    function _getPoolSupply(uint256 _pid) internal view returns (uint256 lpSupply) {\n        PoolInfo memory pool = poolInfo[_pid];\n\n        if (pool.uniStakeContract != address(0)) {\n            lpSupply = IStakingRewards(pool.uniStakeContract).balanceOf(address(this));\n        } else {\n            lpSupply = pool.lpToken.balanceOf(address(this));\n        }\n    }\n\n    // Deposits LP tokens in the specified pool to start earning the user SURF\n    function deposit(uint256 _pid, uint256 _amount) external {\n        depositFor(_pid, msg.sender, _amount);\n    }\n\n    // Deposits LP tokens in the specified pool on behalf of another user\n    function depositFor(uint256 _pid, address _user, uint256 _amount) public {\n        require(msg.sender == tx.origin || contractWhitelist[msg.sender] == true, \"no contracts\");\n        require(surf.maxSupplyHit() != true, \"pools closed\");\n        require(_pid != 0 || surfPoolActive == true, \"surf pool not active\");\n        require(_amount \u003e 0, \"deposit something\");\n\n        updatePool(_pid);\n\n        PoolInfo storage pool = poolInfo[_pid];\n        UserInfo storage user = userInfo[_pid][_user];\n\n        // The sender needs to give approval to the Tito contract for the specified amount of the LP token first\n        pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);\n\n        // Claim any pending SURF and UNI\n        _claimRewardsFromPool(_pid, _user);\n        \n        // Each pool has a 10% staking fee. If staking in the SURF-ETH pool, 100% of the fee gets permanently locked in the SURF contract (gives SURF liquidity forever).\n        // If staking in any other pool, 50% of the fee is used to buyback SURF which is sent to the Whirlpool staking contract where it will start getting distributed to stakers after the max supply is hit, and 50% goes to the team.\n        // The team is never minted or rewarded SURF for any reason to keep things as fair as possible.\n        uint256 stakingFeeAmount = _amount.div(10);\n        uint256 remainingUserAmount = _amount.sub(stakingFeeAmount);\n\n        // If a UNI staking rewards contract is available, use it\n        if (pool.uniStakeContract != address(0)) {\n            pool.lpToken.safeApprove(pool.uniStakeContract, 0);\n            pool.lpToken.approve(pool.uniStakeContract, remainingUserAmount);\n            IStakingRewards(pool.uniStakeContract).stake(remainingUserAmount);\n        }\n\n        // The user is depositing to the SURF-ETH pool so permanently lock all of the LP tokens from the staking fee in the SURF contract\n        if (_pid == 0) {\n            pool.lpToken.transfer(address(surf), stakingFeeAmount);\n        } else {\n            // Remove the liquidity from the pool\n            uint256 deadline = block.timestamp + 5 minutes;\n            pool.lpToken.approve(address(uniswapRouter), stakingFeeAmount);\n            uniswapRouter.removeLiquidityETHSupportingFeeOnTransferTokens(address(pool.token), stakingFeeAmount, 0, 0, address(this), deadline);\n\n            // Swap the ERC-20 token for ETH\n            uint256 ethBalanceBeforeSwap = address(this).balance;\n\n            uint256 tokensToSwap = pool.token.balanceOf(address(this));\n            require(tokensToSwap \u003e 0, \"bad token swap\");\n            address[] memory poolPath = new address[](2);\n            poolPath[0] = address(pool.token);\n            poolPath[1] = address(weth);\n            pool.token.approve(address(uniswapRouter), tokensToSwap);\n            uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(tokensToSwap, 0, poolPath, address(this), deadline);\n\n            uint256 ethBalanceAfterSwap = address(this).balance;\n            uint256 ethReceivedFromStakingFee;\n            uint256 teamFeeAmount;\n\n            // If surfPoolActive == true then perform a buyback of SURF using all of the ETH in the contract and then send it to the Whirlpool staking contract. Otherwise, the ETH will be used to seed the initial liquidity in the SURF-ETH Uniswap pool when activateSurfPool is called\n            if (surfPoolActive == true) {\n                require(ethBalanceAfterSwap \u003e 0, \"bad eth swap\");\n\n                teamFeeAmount = ethBalanceAfterSwap.div(2);\n                ethReceivedFromStakingFee = ethBalanceAfterSwap.sub(teamFeeAmount);\n\n                // The SURF-ETH pool is active, so let\u0027s use the ETH to buyback SURF and send it to the Whirlpool staking contract\n                uint256 surfBought = _buySurf(ethReceivedFromStakingFee);\n\n                // Send the SURF rewards to the Whirlpool staking contract\n                surfSentToWhirlpool += surfBought;\n                _safeSurfTransfer(address(whirlpool), surfBought);\n            } else {\n                ethReceivedFromStakingFee = ethBalanceAfterSwap.sub(ethBalanceBeforeSwap);\n                require(ethReceivedFromStakingFee \u003e 0, \"bad eth swap\");\n\n                teamFeeAmount = ethReceivedFromStakingFee.div(2);\n            }\n\n            if (teamFeeAmount \u003e 0) devAddress.transfer(teamFeeAmount);\n        }\n\n        // Add the remaining amount to the user\u0027s staked balance\n        uint256 _currentRewardDebt = 0;\n        uint256 _currentUniRewardDebt = 0;\n        if (surfPoolActive != true) {\n            _currentRewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(user.rewardDebt);\n            _currentUniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n        }\n        user.staked = user.staked.add(remainingUserAmount);\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(_currentRewardDebt);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12).sub(_currentUniRewardDebt);\n\n        emit Deposit(_user, _pid, _amount);\n    }\n\n    // Internal function that buys back SURF with the amount of ETH specified\n    function _buySurf(uint256 _amount) internal returns (uint256 surfBought) {\n        uint256 ethBalance = address(this).balance;\n        if (_amount \u003e ethBalance) _amount = ethBalance;\n        if (_amount \u003e 0) {\n            uint256 deadline = block.timestamp + 5 minutes;\n            address[] memory surfPath = new address[](2);\n            surfPath[0] = address(weth);\n            surfPath[1] = address(surf);\n            uint256[] memory amounts = uniswapRouter.swapExactETHForTokens{value: _amount}(0, surfPath, address(this), deadline);\n            surfBought = amounts[1];\n        }\n        if (surfBought \u003e 0) emit SurfBuyback(msg.sender, _amount, surfBought);\n    }\n\n    // Internal function to claim earned SURF and UNI from Tito. Claiming won\u0027t work until surfPoolActive == true\n    function _claimRewardsFromPool(uint256 _pid, address _user) internal {\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo storage user = userInfo[_pid][_user];\n\n        if (surfPoolActive != true || user.staked == 0) return;\n\n        uint256 userUniPending = user.staked.mul(pool.accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n        uint256 uniBalance = uniToken.balanceOf(address(this));\n        if (userUniPending \u003e uniBalance) userUniPending = uniBalance;\n        if (userUniPending \u003e 0) {\n            user.uniClaimed += userUniPending;\n            uniToken.transfer(_user, userUniPending);\n        }\n\n        uint256 userSurfPending = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(user.rewardDebt);\n        if (userSurfPending \u003e 0) {\n            user.claimed += userSurfPending;\n            _safeSurfTransfer(_user, userSurfPending);\n        }\n\n        if (userSurfPending \u003e 0 || userUniPending \u003e 0) {\n            emit Claim(_user, _pid, userSurfPending, userUniPending);\n        }\n    }\n\n    // Claim all earned SURF and UNI from a single pool. Claiming won\u0027t work until surfPoolActive == true\n    function claim(uint256 _pid) public {\n        require(surfPoolActive == true, \"surf pool not active\");\n        updatePool(_pid);\n        _claimRewardsFromPool(_pid, msg.sender);\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        PoolInfo memory pool = poolInfo[_pid];\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12);\n    }\n\n    // Claim all earned SURF and UNI from all pools. Claiming won\u0027t work until surfPoolActive == true\n    function claimAll() public {\n        require(surfPoolActive == true, \"surf pool not active\");\n\n        uint256 totalPendingSurfAmount = 0;\n        uint256 totalPendingUniAmount = 0;\n        \n        uint256 length = poolInfo.length;\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            UserInfo storage user = userInfo[pid][msg.sender];\n\n            if (user.staked \u003e 0) {\n                updatePool(pid);\n\n                PoolInfo storage pool = poolInfo[pid];\n                uint256 accSurfPerShare = pool.accSurfPerShare;\n                uint256 accUniPerShare = pool.accUniPerShare;\n\n                uint256 pendingPoolSurfRewards = user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n                user.claimed += pendingPoolSurfRewards;\n                totalPendingSurfAmount = totalPendingSurfAmount.add(pendingPoolSurfRewards);\n                user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n\n                uint256 pendingPoolUniRewards = user.staked.mul(accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n                user.uniClaimed += pendingPoolUniRewards;\n                totalPendingUniAmount = totalPendingUniAmount.add(pendingPoolUniRewards);\n                user.uniRewardDebt = user.staked.mul(accUniPerShare).div(1e12);\n            }\n        }\n\n        require(totalPendingSurfAmount \u003e 0 || totalPendingUniAmount \u003e 0, \"nothing to claim\");\n\n        uint256 uniBalance = uniToken.balanceOf(address(this));\n        if (totalPendingUniAmount \u003e uniBalance) totalPendingUniAmount = uniBalance;\n        if (totalPendingUniAmount \u003e 0) uniToken.transfer(msg.sender, totalPendingUniAmount);\n\n        if (totalPendingSurfAmount \u003e 0) _safeSurfTransfer(msg.sender, totalPendingSurfAmount);\n\n        emit ClaimAll(msg.sender, totalPendingSurfAmount, totalPendingUniAmount);\n    }\n\n    // Withdraw LP tokens and earned SURF from Tito. Withdrawing won\u0027t work until surfPoolActive == true\n    function withdraw(uint256 _pid, uint256 _amount) public {\n        require(surfPoolActive == true, \"surf pool not active\");\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        require(_amount \u003e 0 \u0026\u0026 user.staked \u003e= _amount, \"withdraw: not good\");\n        \n        updatePool(_pid);\n\n        // Claim any pending SURF and UNI\n        _claimRewardsFromPool(_pid, msg.sender);\n\n        PoolInfo memory pool = poolInfo[_pid];\n\n        // If a UNI staking rewards contract is in use, withdraw from it\n        if (pool.uniStakeContract != address(0)) {\n            IStakingRewards(pool.uniStakeContract).withdraw(_amount);\n        }\n\n        user.staked = user.staked.sub(_amount);\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12);\n\n        pool.lpToken.safeTransfer(address(msg.sender), _amount);\n        emit Withdraw(msg.sender, _pid, _amount);\n    }\n\n    // Convenience function to allow users to migrate all of their staked SURF-ETH LP tokens from Tito to the Whirlpool staking contract after the max supply is hit. Migrating won\u0027t work until whirlpool.active() == true\n    function migrateSURFLPtoWhirlpool() public {\n        require(whirlpool.active() == true, \"whirlpool not active\");\n        UserInfo storage user = userInfo[0][msg.sender];\n        uint256 amountToMigrate = user.staked;\n        require(amountToMigrate \u003e 0, \"migrate: not good\");\n        \n        updatePool(0);\n\n        // Claim any pending SURF\n        _claimRewardsFromPool(0, msg.sender);\n\n        user.staked = 0;\n        user.rewardDebt = 0;\n\n        poolInfo[0].lpToken.approve(address(whirlpool), amountToMigrate);\n        whirlpool.stakeFor(msg.sender, amountToMigrate);\n        emit Withdraw(msg.sender, 0, amountToMigrate);\n    }\n\n    // Withdraw without caring about rewards. EMERGENCY ONLY.\n    function emergencyWithdraw(uint256 _pid) public {\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        uint256 staked = user.staked;\n        require(staked \u003e 0, \"no tokens\");\n\n        PoolInfo memory pool = poolInfo[_pid];\n\n        // If a UNI staking rewards contract is in use, withdraw from it\n        if (pool.uniStakeContract != address(0)) {\n            IStakingRewards(pool.uniStakeContract).withdraw(staked);\n        }\n        \n        user.staked = 0;\n        user.rewardDebt = 0;\n        user.uniRewardDebt = 0;\n\n        pool.lpToken.safeTransfer(address(msg.sender), staked);\n        emit EmergencyWithdraw(msg.sender, _pid, staked);\n    }\n\n    // Internal function to safely transfer SURF in case there is a rounding error\n    function _safeSurfTransfer(address _to, uint256 _amount) internal {\n        uint256 surfBalance = surf.balanceOf(address(this));\n        if (_amount \u003e surfBalance) _amount = surfBalance;\n        surf.transfer(_to, _amount);\n    }\n\n    // Creates the SURF-ETH Uniswap pool and adds the initial liqudity that will be permanently locked. Can be called by anyone, but no sooner than 500 blocks after launch. \n    function activateSurfPool() public {\n        require(surfPoolActive == false, \"already active\");\n        require(block.number \u003e startBlock + SOFT_LAUNCH_DURATION.div(2), \"too soon\");\n        uint256 initialEthLiquidity = address(this).balance;\n        require(initialEthLiquidity \u003e 0, \"need ETH\");\n\n        massUpdatePools();\n\n        // The ETH raised from the staking fees collected before surfPoolActive == true is used to seed the ETH side of the SURF-ETH Uniswap pool.\n        // This means that the higher the staking volume during the first 500 blocks, the higher the initial price of SURF\n        if (donatedETH \u003e 0 \u0026\u0026 donatedETH \u003c initialEthLiquidity) initialEthLiquidity = initialEthLiquidity.sub(donatedETH);\n\n        // Mint 1,000,000 new SURF to seed the SURF liquidity in the SURF-ETH Uniswap pool\n        uint256 initialSurfLiquidity = 1000000 * 10**18;\n        surf.mint(address(this), initialSurfLiquidity);\n\n        // Add the liquidity to the SURF-ETH Uniswap pool\n        surf.approve(address(uniswapRouter), initialSurfLiquidity);\n        ( , , uint256 lpTokensReceived) = uniswapRouter.addLiquidityETH{value: initialEthLiquidity}(address(surf), initialSurfLiquidity, 0, 0, address(this), block.timestamp + 5 minutes);\n\n        // Activate the SURF-ETH pool\n        initialSurfPoolETH = initialEthLiquidity;\n        surfPoolActive = true;\n\n        // Permanently lock the LP tokens in the SURF contract\n        IERC20(surfPoolAddress).transfer(address(surf), lpTokensReceived);\n\n        // Buy SURF with all of the donatedETH from partner projects. This SURF will be sent to the Whirlpool staking contract and will start getting distributed to all stakers when the max supply is hit\n        uint256 donatedAmount = donatedETH;\n        uint256 ethBalance = address(this).balance;\n        if (donatedAmount \u003e ethBalance) donatedAmount = ethBalance;\n        if (donatedAmount \u003e 0) {\n            uint256 surfBought = _buySurf(donatedAmount);\n\n            // Send the SURF rewards to the Whirlpool staking contract\n            surfSentToWhirlpool += surfBought;\n            _safeSurfTransfer(address(whirlpool), surfBought);\n            donatedETH = 0;\n        }\n\n        emit SurfPoolActive(msg.sender, initialSurfLiquidity, initialEthLiquidity);\n    }\n\n    // For use by partner teams that are donating to the SURF community. The funds will be used to purchase SURF tokens which will be distributed to stakers once the max supply is hit\n    function donate(address _lpToken) public payable {\n        require(msg.value \u003e= minimumDonationAmount);\n        require(donaters[_lpToken] == address(0));\n\n        donatedETH = donatedETH.add(msg.value);\n        donaters[_lpToken] = msg.sender;\n        donations[_lpToken] = msg.value;\n    }\n\n    // For use by partner teams that donated to the SURF community. The funds can be removed if a beach wasn\u0027t created for the specified lp token (meaning the SURF team didn\u0027t hold up their end of the agreement)\n    function removeDonation(address _lpToken) public {\n        require(block.number \u003c startBlock); // Donations can only be removed if the beach hasn\u0027t been added by the startBlock\n        \n        address returnAddress = donaters[_lpToken];\n        require(msg.sender == returnAddress);\n        \n        uint256 donationAmount = donations[_lpToken];\n        require(donationAmount \u003e 0);\n        \n        uint256 ethBalance = address(this).balance;\n        require(donationAmount \u003c= ethBalance);\n\n        // Only refund the donation if the beach wasn\u0027t created\n        require(existingPools[_lpToken] != true);\n\n        donatedETH = donatedETH.sub(donationAmount);\n        donaters[_lpToken] = address(0);\n        donations[_lpToken] = 0;\n\n        msg.sender.transfer(donationAmount);\n    }\n\n    //////////////////////////\n    // Governance Functions //\n    //////////////////////////\n    // The following functions can only be called by the owner (the SURF token holder governance contract)\n\n    // Sets the address of the Whirlpool staking contract that bought SURF gets sent to for distribution to stakers once the max supply is hit\n    function setWhirlpoolContract(Whirlpool _whirlpool) public onlyOwner {\n        whirlpool = _whirlpool;\n    }\n\n    // Add a new LP Token pool\n    function addPool(address _token, address _lpToken, uint256 _apr, bool _requireDonation) public onlyOwner {\n        require(surf.maxSupplyHit() != true);\n        require(existingPools[_lpToken] != true, \"pool exists\");\n        require(_requireDonation != true || donations[_lpToken] \u003e= minimumDonationAmount, \"must donate\");\n\n        _addPool(_token, _lpToken);\n        if (_apr != DEFAULT_APR) poolInfo[poolInfo.length-1].apr = _apr;\n    }\n\n    // Update the given pool\u0027s APR\n    function setApr(uint256 _pid, uint256 _apr) public onlyOwner {\n        require(surf.maxSupplyHit() != true);\n        updatePool(_pid);\n        poolInfo[_pid].apr = _apr;\n    }\n\n    // Add a contract to the whitelist so that it can interact with Tito. This is needed for the Aegis pool contract to be able to stake on behalf of everyone in the pool.\n    // We want limited interaction from contracts due to the growing \"flash loan\" trend that can be used to dramatically manipulate a token\u0027s price in a single block.\n    function addToWhitelist(address _contractAddress) public onlyOwner {\n        contractWhitelist[_contractAddress] = true;\n    }\n\n    // Remove a contract from the whitelist\n    function removeFromWhitelist(address _contractAddress) public onlyOwner {\n        contractWhitelist[_contractAddress] = false;\n    }\n\n}"},"UniStakingInterfaces.sol":{"content":"pragma solidity ^0.6.12;\n\ninterface StakingRewardsFactory {\n    function stakingRewardsInfoByStakingToken(address) external view returns (address, uint256);\n}\n\ninterface IStakingRewards {\n    // Views\n    function lastTimeRewardApplicable() external view returns (uint256);\n\n    function rewardPerToken() external view returns (uint256);\n\n    function earned(address account) external view returns (uint256);\n\n    function getRewardForDuration() external view returns (uint256);\n\n    function totalSupply() external view returns (uint256);\n\n    function balanceOf(address account) external view returns (uint256);\n\n    // Mutative\n\n    function stake(uint256 amount) external;\n\n    function withdraw(uint256 amount) external;\n\n    function getReward() external;\n\n    function exit() external;\n}"},"Whirlpool.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./SafeERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./IUniswapV2Router02.sol\u0027;\nimport \u0027./SURF.sol\u0027;\nimport \u0027./Tito.sol\u0027;\n\n// The Whirlpool staking contract becomes active after the max supply it hit, and is where SURF-ETH LP token stakers will continue to receive dividends from other projects in the SURF ecosystem\ncontract Whirlpool is Ownable {\n    using SafeMath for uint256;\n    using SafeERC20 for IERC20;\n\n    // Info of each user\n    struct UserInfo {\n        uint256 staked; // How many SURF-ETH LP tokens the user has staked\n        uint256 rewardDebt; // Reward debt. Works the same as in the Tito contract\n        uint256 claimed; // Tracks the amount of SURF claimed by the user\n    }\n\n    // The SURF TOKEN!\n    SURF public surf;\n    // The Tito contract\n    Tito public tito;\n    // The SURF-ETH Uniswap LP token\n    IERC20 public surfPool;\n    // The Uniswap v2 Router\n    IUniswapV2Router02 public uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);\n    // WETH\n    IERC20 public weth;\n\n    // Info of each user that stakes SURF-ETH LP tokens\n    mapping (address =\u003e UserInfo) public userInfo;\n    // The amount of SURF sent to this contract before it became active\n    uint256 public initialSurfReward = 0;\n    // 1% of the initialSurfReward will be rewarded to stakers per day for 100 days\n    uint256 public initialSurfRewardPerDay;\n    // How often the initial 1% payouts can be processed\n    uint256 public constant INITIAL_PAYOUT_INTERVAL = 24 hours;\n    // The unstaking fee that is used to increase locked liquidity and reward Whirlpool stakers (1 = 0.1%). Defaults to 10%\n    uint256 public unstakingFee = 100;\n    // The amount of SURF-ETH LP tokens kept by the unstaking fee that will be converted to SURF and distributed to stakers (1 = 0.1%). Defaults to 50%\n    uint256 public unstakingFeeConvertToSurfAmount = 500;\n    // When the first 1% payout can be processed (timestamp). It will be 24 hours after the Whirlpool contract is activated\n    uint256 public startTime;\n    // When the last 1% payout was processed (timestamp)\n    uint256 public lastPayout;\n    // The total amount of pending SURF available for stakers to claim\n    uint256 public totalPendingSurf;\n    // Accumulated SURFs per share, times 1e12.\n    uint256 public accSurfPerShare;\n    // The total amount of SURF-ETH LP tokens staked in the contract\n    uint256 public totalStaked;\n    // Becomes true once the \u0027activate\u0027 function called by the Tito contract when the max SURF supply is hit\n    bool public active = false;\n\n    event Stake(address indexed user, uint256 amount);\n    event Claim(address indexed user, uint256 surfAmount);\n    event Withdraw(address indexed user, uint256 amount);\n    event SurfRewardAdded(address indexed user, uint256 surfReward);\n    event EthRewardAdded(address indexed user, uint256 ethReward);\n\n    constructor(SURF _surf, Tito _tito) public {\n        tito = _tito;\n        surf = _surf;\n        surfPool = IERC20(tito.surfPoolAddress());\n        weth = IERC20(uniswapRouter.WETH());\n    }\n\n    receive() external payable {\n        emit EthRewardAdded(msg.sender, msg.value);\n    }\n\n    function activate() public {\n        require(active != true, \"already active\");\n        require(surf.maxSupplyHit() == true, \"too soon\");\n\n        active = true;\n\n        // Now that the Whirlpool staking contract is active, reward 1% of the initialSurfReward per day for 100 days\n        startTime = block.timestamp + INITIAL_PAYOUT_INTERVAL; // The first payout can be processed 24 hours after activation\n        lastPayout = startTime;\n        initialSurfRewardPerDay = initialSurfReward.div(100);\n    }\n\n    // The _transfer function in the SURF contract calls this to let the Whirlpool contract know that it received the specified amount of SURF to be distributed to stakers \n    function addSurfReward(address _from, uint256 _amount) public {\n        require(msg.sender == address(surf), \"not surf contract\");\n        require(tito.surfPoolActive() == true, \"no surf pool\");\n        require(_amount \u003e 0, \"no surf\");\n\n        if (active != true || totalStaked == 0) {\n            initialSurfReward = initialSurfReward.add(_amount);\n        } else {\n            totalPendingSurf = totalPendingSurf.add(_amount);\n            accSurfPerShare = accSurfPerShare.add(_amount.mul(1e12).div(totalStaked));\n        }\n\n        emit SurfRewardAdded(_from, _amount);\n    }\n\n    // Allows external sources to add ETH to the contract which is used to buy and then distribute SURF to stakers\n    function addEthReward() public payable {\n        require(tito.surfPoolActive() == true, \"no surf pool\");\n\n        // We will purchase SURF with all of the ETH in the contract in case some was sent directly to the contract instead of using addEthReward\n        uint256 ethBalance = address(this).balance;\n        require(ethBalance \u003e 0, \"no eth\");\n\n        // Use the ETH to buyback SURF which will be distributed to stakers\n        _buySurf(ethBalance);\n\n        // The _transfer function in the SURF contract calls the Whirlpool contract\u0027s updateSurfReward function so we don\u0027t need to update the balances after buying the SURF\n        emit EthRewardAdded(msg.sender, msg.value);\n    }\n\n    // Internal function to buy back SURF with the amount of ETH specified\n    function _buySurf(uint256 _amount) internal {\n        uint256 deadline = block.timestamp + 5 minutes;\n        address[] memory surfPath = new address[](2);\n        surfPath[0] = address(weth);\n        surfPath[1] = address(surf);\n        uniswapRouter.swapExactETHForTokens{value: _amount}(0, surfPath, address(this), deadline);\n    }\n\n    // Handles paying out the initialSurfReward over 100 days\n    function _processInitialPayouts() internal {\n        if (active != true || block.timestamp \u003c startTime || initialSurfReward == 0 || totalStaked == 0) return;\n\n        // How many days since last payout?\n        uint256 daysSinceLastPayout = (block.timestamp - lastPayout) / INITIAL_PAYOUT_INTERVAL;\n\n        // If less than 1, don\u0027t do anything\n        if (daysSinceLastPayout == 0) return;\n\n        // Work out how many payouts have been missed\n        uint256 nextPayoutNumber = (block.timestamp - startTime) / INITIAL_PAYOUT_INTERVAL;\n        uint256 previousPayoutNumber = nextPayoutNumber - daysSinceLastPayout;\n\n        // Calculate how much additional reward we have to hand out\n        uint256 surfReward = rewardAtPayout(nextPayoutNumber) - rewardAtPayout(previousPayoutNumber);\n        if (surfReward \u003e initialSurfReward) surfReward = initialSurfReward;\n        initialSurfReward = initialSurfReward.sub(surfReward);\n\n        // Payout the surfReward to the stakers\n        totalPendingSurf = totalPendingSurf.add(surfReward);\n        accSurfPerShare = accSurfPerShare.add(surfReward.mul(1e12).div(totalStaked));\n\n        // Update lastPayout time\n        lastPayout += (daysSinceLastPayout * INITIAL_PAYOUT_INTERVAL);\n    }\n\n    // Handles claiming the user\u0027s pending SURF rewards\n    function _claimReward(address _user) internal {\n        UserInfo storage user = userInfo[_user];\n        if (user.staked \u003e 0) {\n            uint256 pendingSurfReward = user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n            if (pendingSurfReward \u003e 0) {\n                totalPendingSurf = totalPendingSurf.sub(pendingSurfReward);\n                user.claimed += pendingSurfReward;\n                _safeSurfTransfer(_user, pendingSurfReward);\n                emit Claim(_user, pendingSurfReward);\n            }\n        }\n    }\n\n    // Stake SURF-ETH LP tokens to get rewarded with more SURF\n    function stake(uint256 _amount) public {\n        stakeFor(msg.sender, _amount);\n    }\n\n    // Stake SURF-ETH LP tokens on behalf of another address\n    function stakeFor(address _user, uint256 _amount) public {\n        require(active == true, \"not active\");\n        require(_amount \u003e 0, \"stake something\");\n\n        _processInitialPayouts();\n\n        // Claim any pending SURF\n        _claimReward(_user);\n\n        surfPool.safeTransferFrom(address(msg.sender), address(this), _amount);\n\n        UserInfo storage user = userInfo[_user];\n        totalStaked = totalStaked.add(_amount);\n        user.staked = user.staked.add(_amount);\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n        emit Stake(_user, _amount);\n    }\n\n    // Claim earned SURF. Claiming won\u0027t work until active == true\n    function claim() public {\n        require(active == true, \"not active\");\n        UserInfo storage user = userInfo[msg.sender];\n        require(user.staked \u003e 0, \"no stake\");\n        \n        _processInitialPayouts();\n\n        // Claim any pending SURF\n        _claimReward(msg.sender);\n\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n    }\n\n    // Unstake and withdraw SURF-ETH LP tokens and any pending SURF rewards. There is a 10% unstaking fee, meaning the user will only receive 90% of their LP tokens back.\n    // For the LP tokens kept by the unstaking fee, 50% will get locked forever in the SURF contract, and 50% will get converted to SURF and distributed to stakers.\n    function withdraw(uint256 _amount) public {\n        require(active == true, \"not active\");\n        UserInfo storage user = userInfo[msg.sender];\n        require(_amount \u003e 0 \u0026\u0026 user.staked \u003e= _amount, \"withdraw: not good\");\n        \n        _processInitialPayouts();\n\n        uint256 unstakingFeeAmount = _amount.mul(unstakingFee).div(1000);\n        uint256 remainingUserAmount = _amount.sub(unstakingFeeAmount);\n\n        // Half of the LP tokens kept by the unstaking fee will be locked forever in the SURF contract, the other half will be converted to SURF and distributed to stakers\n        uint256 lpTokensToConvertToSurf = unstakingFeeAmount.mul(unstakingFeeConvertToSurfAmount).div(1000);\n        uint256 lpTokensToLock = unstakingFeeAmount.sub(lpTokensToConvertToSurf);\n\n        // Remove the liquidity from the Uniswap SURF-ETH pool and buy SURF with the ETH received\n        // The _transfer function in the SURF.sol contract automatically calls whirlpool.addSurfReward() so we don\u0027t have to in this function\n        if (lpTokensToConvertToSurf \u003e 0) {\n            surfPool.approve(address(uniswapRouter), lpTokensToConvertToSurf);\n            uniswapRouter.removeLiquidityETHSupportingFeeOnTransferTokens(address(surf), lpTokensToConvertToSurf, 0, 0, address(this), block.timestamp + 5 minutes);\n            addEthReward();\n        }\n\n        // Permanently lock the LP tokens in the SURF contract\n        if (lpTokensToLock \u003e 0) surfPool.transfer(address(surf), lpTokensToLock);\n\n        // Claim any pending SURF\n        _claimReward(msg.sender);\n\n        totalStaked = totalStaked.sub(_amount);\n        user.staked = user.staked.sub(_amount);\n        surfPool.safeTransfer(address(msg.sender), remainingUserAmount);\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n        emit Withdraw(msg.sender, remainingUserAmount);\n    }\n\n    // Internal function to safely transfer SURF in case there is a rounding error\n    function _safeSurfTransfer(address _to, uint256 _amount) internal {\n        uint256 surfBal = surf.balanceOf(address(this));\n        if (_amount \u003e surfBal) {\n            surf.transfer(_to, surfBal);\n        } else {\n            surf.transfer(_to, _amount);\n        }\n    }\n\n    // Sets the unstaking fee. Can\u0027t be higher than 50%. _convertToSurfAmount is the % of the LP tokens from the unstaking fee that will be converted to SURF and distributed to stakers.\n    // unstakingFee - unstakingFeeConvertToSurfAmount = The % of the LP tokens from the unstaking fee that will be permanently locked in the SURF contract\n    function setUnstakingFee(uint256 _unstakingFee, uint256 _convertToSurfAmount) public onlyOwner {\n        require(_unstakingFee \u003c= 500, \"over 50%\");\n        require(_convertToSurfAmount \u003c= 1000, \"bad amount\");\n        unstakingFee = _unstakingFee;\n        unstakingFeeConvertToSurfAmount = _convertToSurfAmount;\n    }\n\n    // Function to recover ERC20 tokens accidentally sent to the contract.\n    // SURF and SURF-ETH LP tokens (the only 2 ERC2O\u0027s that should be in this contract) can\u0027t be withdrawn this way.\n    function recoverERC20(address _tokenAddress) public onlyOwner {\n        require(_tokenAddress != address(surf) \u0026\u0026 _tokenAddress != address(surfPool));\n        IERC20 token = IERC20(_tokenAddress);\n        uint256 tokenBalance = token.balanceOf(address(this));\n        token.transfer(msg.sender, tokenBalance);\n    }\n\n    function payoutNumber() public view returns (uint256) {\n        if (block.timestamp \u003c startTime) return 0;\n\n        uint256 payout = (block.timestamp - startTime).div(INITIAL_PAYOUT_INTERVAL);\n        if (payout \u003e 100) return 100;\n        else return payout;\n    }\n\n    function timeUntilNextPayout() public view returns (uint256) {\n        if (initialSurfReward == 0) return 0;\n        else {\n            uint256 payout = payoutNumber();\n            uint256 nextPayout = startTime.add((payout + 1).mul(INITIAL_PAYOUT_INTERVAL));\n            return nextPayout - block.timestamp;\n        }\n    }\n\n    function rewardAtPayout(uint256 _payoutNumber) public view returns (uint256) {\n        if (_payoutNumber == 0) return 0;\n        return initialSurfRewardPerDay * _payoutNumber;\n    }\n\n    function getAllInfoFor(address _user) external view returns (bool isActive, uint256[12] memory info) {\n        isActive = active;\n        info[0] = surf.balanceOf(address(this));\n        info[1] = initialSurfReward;\n        info[2] = totalPendingSurf;\n        info[3] = startTime;\n        info[4] = lastPayout;\n        info[5] = totalStaked;\n        info[6] = surf.balanceOf(_user);\n        if (tito.surfPoolActive()) {\n            info[7] = surfPool.balanceOf(_user);\n            info[8] = surfPool.allowance(_user, address(this));\n        }\n        info[9] = userInfo[_user].staked;\n        info[10] = userInfo[_user].staked.mul(accSurfPerShare).div(1e12).sub(userInfo[_user].rewardDebt);\n        info[11] = userInfo[_user].claimed;\n    }\n\n}"}}

{"Address.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts\n        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned\n        // for accounts without code, i.e. `keccak256(\u0027\u0027)`\n        bytes32 codehash;\n        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { codehash := extcodehash(account) }\n        return (codehash != accountHash \u0026\u0026 codehash != 0x0);\n    }\n\n    /**\n     * @dev Replacement for Solidity\u0027s `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance \u003e= amount, \"Address: insufficient balance\");\n\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\n        (bool success, ) = recipient.call{ value: amount }(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain`call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n      return functionCall(target, data, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\n        return _functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {\n        require(address(this).balance \u003e= value, \"Address: insufficient balance for call\");\n        return _functionCallWithValue(target, data, value, errorMessage);\n    }\n\n    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {\n        require(isContract(target), \"Address: call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);\n        if (success) {\n            return returndata;\n        } else {\n            // Look for revert reason and bubble it up if present\n            if (returndata.length \u003e 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\n                // solhint-disable-next-line no-inline-assembly\n                assembly {\n                    let returndata_size := mload(returndata)\n                    revert(add(32, returndata), returndata_size)\n                }\n            } else {\n                revert(errorMessage);\n            }\n        }\n    }\n}"},"Context.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/GSN/Context.sol\n\n/*\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with GSN meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address payable) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes memory) {\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n        return msg.data;\n    }\n}"},"ERC20.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./Context.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\n\n// File: @openzeppelin/contracts/token/ERC20/ERC20.sol\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * We have followed general OpenZeppelin guidelines: functions revert instead\n * of returning `false` on failure. This behavior is nonetheless conventional\n * and does not conflict with the expectations of ERC20 applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn\u0027t required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract ERC20 is Context, IERC20 {\n    using SafeMath for uint256;\n\n    mapping (address =\u003e uint256) internal _balances;\n\n    mapping (address =\u003e mapping (address =\u003e uint256)) private _allowances;\n\n    uint256 private _totalSupply;\n\n    string private _name;\n    string private _symbol;\n    uint8 private _decimals;\n\n    /**\n     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with\n     * a default value of 18.\n     *\n     * To select a different value for {decimals}, use {_setupDecimals}.\n     *\n     * All three of these values are immutable: they can only be set once during\n     * construction.\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n        _decimals = 18;\n    }\n\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() public view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Returns the symbol of the token, usually a shorter version of the\n     * name.\n     */\n    function symbol() public view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns the number of decimals used to get its user representation.\n     * For example, if `decimals` equals `2`, a balance of `505` tokens should\n     * be displayed to a user as `5,05` (`505 / 10 ** 2`).\n     *\n     * Tokens usually opt for a value of 18, imitating the relationship between\n     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is\n     * called.\n     *\n     * NOTE: This information is only used for _display_ purposes: it in\n     * no way affects any of the arithmetic of the contract, including\n     * {IERC20-balanceOf} and {IERC20-transfer}.\n     */\n    function decimals() public view override returns (uint8) {\n        return _decimals;\n    }\n\n    /**\n     * @dev See {IERC20-totalSupply}.\n     */\n    function totalSupply() public view override returns (uint256) {\n        return _totalSupply;\n    }\n\n    /**\n     * @dev See {IERC20-balanceOf}.\n     */\n    function balanceOf(address account) public view override returns (uint256) {\n        return _balances[account];\n    }\n\n    /**\n     * @dev See {IERC20-transfer}.\n     *\n     * Requirements:\n     *\n     * - `recipient` cannot be the zero address.\n     * - the caller must have a balance of at least `amount`.\n     */\n    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(_msgSender(), recipient, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-allowance}.\n     */\n    function allowance(address owner, address spender) public view virtual override returns (uint256) {\n        return _allowances[owner][spender];\n    }\n\n    /**\n     * @dev See {IERC20-approve}.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function approve(address spender, uint256 amount) public virtual override returns (bool) {\n        _approve(_msgSender(), spender, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-transferFrom}.\n     *\n     * Emits an {Approval} event indicating the updated allowance. This is not\n     * required by the EIP. See the note at the beginning of {ERC20};\n     *\n     * Requirements:\n     * - `sender` and `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     * - the caller must have allowance for ``sender``\u0027s tokens of at least\n     * `amount`.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(sender, recipient, amount);\n        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"ERC20: transfer amount exceeds allowance\"));\n        return true;\n    }\n\n    /**\n     * @dev Atomically increases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\n        return true;\n    }\n\n    /**\n     * @dev Atomically decreases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `spender` must have allowance for the caller of at least\n     * `subtractedValue`.\n     */\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"ERC20: decreased allowance below zero\"));\n        return true;\n    }\n\n    /**\n     * @dev Moves tokens `amount` from `sender` to `recipient`.\n     *\n     * This is internal function is equivalent to {transfer}, and can be used to\n     * e.g. implement automatic token fees, slashing mechanisms, etc.\n     *\n     * Emits a {Transfer} event.\n     *\n     * Requirements:\n     *\n     * - `sender` cannot be the zero address.\n     * - `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     */\n    function _transfer(address sender, address recipient, uint256 amount) internal virtual {\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        _beforeTokenTransfer(sender, recipient, amount);\n\n        _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n        _balances[recipient] = _balances[recipient].add(amount);\n        emit Transfer(sender, recipient, amount);\n    }\n\n    /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n     * the total supply.\n     *\n     * Emits a {Transfer} event with `from` set to the zero address.\n     *\n     * Requirements\n     *\n     * - `to` cannot be the zero address.\n     */\n    function _mint(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: mint to the zero address\");\n\n        _beforeTokenTransfer(address(0), account, amount);\n\n        _totalSupply = _totalSupply.add(amount);\n        _balances[account] = _balances[account].add(amount);\n        emit Transfer(address(0), account, amount);\n    }\n\n    /**\n     * @dev Destroys `amount` tokens from `account`, reducing the\n     * total supply.\n     *\n     * Emits a {Transfer} event with `to` set to the zero address.\n     *\n     * Requirements\n     *\n     * - `account` cannot be the zero address.\n     * - `account` must have at least `amount` tokens.\n     */\n    function _burn(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: burn from the zero address\");\n\n        _beforeTokenTransfer(account, address(0), amount);\n\n        _balances[account] = _balances[account].sub(amount, \"ERC20: burn amount exceeds balance\");\n        _totalSupply = _totalSupply.sub(amount);\n        emit Transfer(account, address(0), amount);\n    }\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.\n     *\n     * This is internal function is equivalent to `approve`, and can be used to\n     * e.g. set automatic allowances for certain subsystems, etc.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `owner` cannot be the zero address.\n     * - `spender` cannot be the zero address.\n     */\n    function _approve(address owner, address spender, uint256 amount) internal virtual {\n        require(owner != address(0), \"ERC20: approve from the zero address\");\n        require(spender != address(0), \"ERC20: approve to the zero address\");\n\n        _allowances[owner][spender] = amount;\n        emit Approval(owner, spender, amount);\n    }\n\n    /**\n     * @dev Sets {decimals} to a value other than the default one of 18.\n     *\n     * WARNING: This function should only be called from the constructor. Most\n     * applications that interact with token contracts will not expect\n     * {decimals} to ever change, and may work incorrectly if it does.\n     */\n    function _setupDecimals(uint8 decimals_) internal {\n        _decimals = decimals_;\n    }\n\n    /**\n     * @dev Hook that is called before any transfer of tokens. This includes\n     * minting and burning.\n     *\n     * Calling conditions:\n     *\n     * - when `from` and `to` are both non-zero, `amount` of ``from``\u0027s tokens\n     * will be to transferred to `to`.\n     * - when `from` is zero, `amount` tokens will be minted for `to`.\n     * - when `to` is zero, `amount` of ``from``\u0027s tokens will be burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }\n}"},"IERC20.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/token/ERC20/IERC20.sol\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Returns the number of decimal places.\n     */\n    function decimals() external view returns (uint8);\n\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller\u0027s account to `recipient`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n}"},"IUniswapV2Pair.sol":{"content":"\npragma solidity ^0.6.12;\n\ninterface IUniswapV2Pair {\n    event Approval(address indexed owner, address indexed spender, uint value);\n    event Transfer(address indexed from, address indexed to, uint value);\n\n    function name() external pure returns (string memory);\n    function symbol() external pure returns (string memory);\n    function decimals() external pure returns (uint8);\n    function totalSupply() external view returns (uint);\n    function balanceOf(address owner) external view returns (uint);\n    function allowance(address owner, address spender) external view returns (uint);\n\n    function approve(address spender, uint value) external returns (bool);\n    function transfer(address to, uint value) external returns (bool);\n    function transferFrom(address from, address to, uint value) external returns (bool);\n\n    function DOMAIN_SEPARATOR() external view returns (bytes32);\n    function PERMIT_TYPEHASH() external pure returns (bytes32);\n    function nonces(address owner) external view returns (uint);\n\n    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;\n\n    event Mint(address indexed sender, uint amount0, uint amount1);\n    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);\n    event Swap(\n        address indexed sender,\n        uint amount0In,\n        uint amount1In,\n        uint amount0Out,\n        uint amount1Out,\n        address indexed to\n    );\n    event Sync(uint112 reserve0, uint112 reserve1);\n\n    function MINIMUM_LIQUIDITY() external pure returns (uint);\n    function factory() external view returns (address);\n    function token0() external view returns (address);\n    function token1() external view returns (address);\n    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);\n    function price0CumulativeLast() external view returns (uint);\n    function price1CumulativeLast() external view returns (uint);\n    function kLast() external view returns (uint);\n\n    function mint(address to) external returns (uint liquidity);\n    function burn(address to) external returns (uint amount0, uint amount1);\n    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;\n    function skim(address to) external;\n    function sync() external;\n\n    function initialize(address, address) external;\n}"},"IUniswapV2Router02.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol\n\ninterface IUniswapV2Router01 {\n    function factory() external pure returns (address);\n    function WETH() external pure returns (address);\n\n    function addLiquidity(\n        address tokenA,\n        address tokenB,\n        uint amountADesired,\n        uint amountBDesired,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountA, uint amountB, uint liquidity);\n    function addLiquidityETH(\n        address token,\n        uint amountTokenDesired,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);\n    function removeLiquidity(\n        address tokenA,\n        address tokenB,\n        uint liquidity,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountA, uint amountB);\n    function removeLiquidityETH(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountToken, uint amountETH);\n    function removeLiquidityWithPermit(\n        address tokenA,\n        address tokenB,\n        uint liquidity,\n        uint amountAMin,\n        uint amountBMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountA, uint amountB);\n    function removeLiquidityETHWithPermit(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountToken, uint amountETH);\n    function swapExactTokensForTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external returns (uint[] memory amounts);\n    function swapTokensForExactTokens(\n        uint amountOut,\n        uint amountInMax,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external returns (uint[] memory amounts);\n    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)\n        external\n        payable\n        returns (uint[] memory amounts);\n    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)\n        external\n        returns (uint[] memory amounts);\n    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)\n        external\n        returns (uint[] memory amounts);\n    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)\n        external\n        payable\n        returns (uint[] memory amounts);\n\n    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);\n    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);\n    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);\n    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);\n    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);\n}\n\ninterface IUniswapV2Router02 is IUniswapV2Router01 {\n    function removeLiquidityETHSupportingFeeOnTransferTokens(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline\n    ) external returns (uint amountETH);\n    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(\n        address token,\n        uint liquidity,\n        uint amountTokenMin,\n        uint amountETHMin,\n        address to,\n        uint deadline,\n        bool approveMax, uint8 v, bytes32 r, bytes32 s\n    ) external returns (uint amountETH);\n\n    function swapExactTokensForTokensSupportingFeeOnTransferTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external;\n    function swapExactETHForTokensSupportingFeeOnTransferTokens(\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external payable;\n    function swapExactTokensForETHSupportingFeeOnTransferTokens(\n        uint amountIn,\n        uint amountOutMin,\n        address[] calldata path,\n        address to,\n        uint deadline\n    ) external;\n}"},"Ownable.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./Context.sol\u0027;\n\n// File: @openzeppelin/contracts/access/Ownable.sol\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\ncontract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor () internal {\n        address msgSender = _msgSender();\n        _owner = msgSender;\n        emit OwnershipTransferred(address(0), msgSender);\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        require(_owner == _msgSender(), \"Ownable: caller is not the owner\");\n        _;\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        emit OwnershipTransferred(_owner, address(0));\n        _owner = address(0);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        emit OwnershipTransferred(_owner, newOwner);\n        _owner = newOwner;\n    }\n}"},"SafeERC20.sol":{"content":"pragma solidity ^0.6.12;\n\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./Address.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\n\n// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n    using SafeMath for uint256;\n    using Address for address;\n\n    function safeTransfer(IERC20 token, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n    }\n\n    /**\n     * @dev Deprecated. This function has issues similar to the ones found in\n     * {IERC20-approve}, and its usage is discouraged.\n     *\n     * Whenever possible, use {safeIncreaseAllowance} and\n     * {safeDecreaseAllowance} instead.\n     */\n    function safeApprove(IERC20 token, address spender, uint256 value) internal {\n        // safeApprove should only be called when setting an initial allowance,\n        // or when resetting it to zero. To increase and decrease it, use\n        // \u0027safeIncreaseAllowance\u0027 and \u0027safeDecreaseAllowance\u0027\n        // solhint-disable-next-line max-line-length\n        require((value == 0) || (token.allowance(address(this), spender) == 0),\n            \"SafeERC20: approve from non-zero to non-zero allowance\"\n        );\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n    }\n\n    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).add(value);\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).sub(value, \"SafeERC20: decreased allowance below zero\");\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     */\n    function _callOptionalReturn(IERC20 token, bytes memory data) private {\n        // We need to perform a low level call here, to bypass Solidity\u0027s return data size checking mechanism, since\n        // we\u0027re implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that\n        // the target address contains contract code and also asserts for success in the low-level call.\n\n        bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n        if (returndata.length \u003e 0) { // Return data is optional\n            // solhint-disable-next-line max-line-length\n            require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n        }\n    }\n}"},"SafeMath.sol":{"content":"pragma solidity ^0.6.12;\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\n/**\n * @dev Wrappers over Solidity\u0027s arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it\u0027s recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c \u003e= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        return sub(a, b, \"SafeMath: subtraction overflow\");\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003c= a, errorMessage);\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\n        // benefit is lost if \u0027b\u0027 is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        return div(a, b, \"SafeMath: division by zero\");\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003e 0, errorMessage);\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn\u0027t hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        return mod(a, b, \"SafeMath: modulo by zero\");\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts with custom message when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b != 0, errorMessage);\n        return a % b;\n    }\n}"},"SURF.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./ERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./Whirlpool.sol\u0027;\n\ninterface Callable {\n    function tokenCallback(address _from, uint256 _tokens, bytes calldata _data) external returns (bool);\n    function receiveApproval(address _from, uint256 _tokens, address _token, bytes calldata _data) external;\n}\n\n// SURF Token with Governance. The governance contract will own the SURF, Tito, and Whirlpool contracts,\n// allowing SURF token holders to make and vote on proposals that can modify many parts of the protocol.\ncontract SURF is ERC20(\"SURF.Finance\", \"SURF\"), Ownable {\n\n    // There will be a max supply of 10,000,000 SURF tokens\n    uint256 public constant MAX_SUPPLY = 10000000 * 10**18;\n    bool public maxSupplyHit = false;\n\n    // The SURF transfer fee that gets rewarded to Whirlpool stakers (1 = 0.1%). Defaults to 1%\n    uint256 public transferFee = 10;\n\n    // Mapping of whitelisted sender and recipient addresses that don\u0027t pay the transfer fee. Allows SURF token holders to whitelist future contracts\n    mapping(address =\u003e bool) public senderWhitelist;\n    mapping(address =\u003e bool) public recipientWhitelist;\n\n    // The Tito contract\n    address public titoAddress;\n\n    // The Whirlpool contract\n    address payable public whirlpoolAddress;\n\n    // The Uniswap SURF-ETH LP token address\n    address public surfPoolAddress;\n\n    // Creates `_amount` token to `_to`. Can only be called by the Tito contract.\n    function mint(address _to, uint256 _amount) public {\n        require(maxSupplyHit != true, \"max supply hit\");\n        require(msg.sender == titoAddress, \"not Tito\");\n        uint256 supply = totalSupply();\n        if (supply.add(_amount) \u003e= MAX_SUPPLY) {\n            _amount = MAX_SUPPLY.sub(supply);\n            maxSupplyHit = true;\n        }\n\n        if (_amount \u003e 0) {\n            _mint(_to, _amount);\n            _moveDelegates(address(0), _delegates[_to], _amount);\n        }\n    }\n\n    // Sets the addresses of the Tito farming contract, the Whirlpool staking contract, and the Uniswap SURF-ETH LP token\n    function setContractAddresses(address _titoAddress, address payable _whirlpoolAddress, address _surfPoolAddress) public onlyOwner {\n        if (_titoAddress != address(0)) titoAddress = _titoAddress;\n        if (_whirlpoolAddress != address(0)) whirlpoolAddress = _whirlpoolAddress;\n        if (_surfPoolAddress != address(0)) surfPoolAddress = _surfPoolAddress;\n    }\n\n    // Sets the SURF transfer fee that gets rewarded to Whirlpool stakers. Can\u0027t be higher than 10%.\n    function setTransferFee(uint256 _transferFee) public onlyOwner {\n        require(_transferFee \u003c= 100, \"over 10%\");\n        transferFee = _transferFee;\n    }\n\n    // Add an address to the sender or recipient transfer whitelist\n    function addToTransferWhitelist(bool _addToSenderWhitelist, address _address) public onlyOwner {\n        if (_addToSenderWhitelist == true) senderWhitelist[_address] = true;\n        else recipientWhitelist[_address] = true;\n    }\n\n    // Remove an address from the sender or recipient transfer whitelist\n    function removeFromTransferWhitelist(bool _removeFromSenderWhitelist, address _address) public onlyOwner {\n        if (_removeFromSenderWhitelist == true) senderWhitelist[_address] = false;\n        else recipientWhitelist[_address] = false;\n    }\n\n    // Both the Tito and Whirlpool contracts will lock the SURF-ETH LP tokens they receive from their staking/unstaking fees here (ensuring liquidity forever).\n    // This function allows SURF token holders to decide what to do with the locked LP tokens in the future\n    function migrateLockedLPTokens(address _to, uint256 _amount) public onlyOwner {\n        IERC20 surfPool = IERC20(surfPoolAddress);\n        require(_amount \u003e 0 \u0026\u0026 _amount \u003c= surfPool.balanceOf(address(this)), \"bad amount\");\n        surfPool.transfer(_to, _amount);\n    }\n\n    function approveAndCall(address _spender, uint256 _tokens, bytes calldata _data) external returns (bool) {\n        approve(_spender, _tokens);\n        Callable(_spender).receiveApproval(msg.sender, _tokens, address(this), _data);\n        return true;\n    }\n\n    function transferAndCall(address _to, uint256 _tokens, bytes calldata _data) external returns (bool) {\n        uint256 _balanceBefore = balanceOf(_to);\n        transfer(_to, _tokens);\n        uint256 _tokensReceived = balanceOf(_to) - _balanceBefore;\n        uint32 _size;\n        assembly {\n            _size := extcodesize(_to)\n        }\n        if (_size \u003e 0) {\n            require(Callable(_to).tokenCallback(msg.sender, _tokensReceived, _data));\n        }\n        return true;\n    }\n\n    // There\u0027s a fee on every SURF transfer that gets sent to the Whirlpool staking contract which will start getting rewarded to stakers after the max supply is hit.\n    // The transfer fee will reduce the front-running of Uniswap trades and will provide a major incentive to hold and stake SURF long-term.\n    // Transfers to/from the Tito or Whirlpool contracts will not pay a fee.\n    function _transfer(address sender, address recipient, uint256 amount) internal override {\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        uint256 transferFeeAmount;\n        uint256 tokensToTransfer;\n\n        if (amount \u003e 0) {\n\n            // Send a fee to the Whirlpool staking contract if this isn\u0027t a whitelisted transfer\n            if (_isWhitelistedTransfer(sender, recipient) != true) {\n                transferFeeAmount = amount.mul(transferFee).div(1000);\n                _balances[whirlpoolAddress] = _balances[whirlpoolAddress].add(transferFeeAmount);\n                _moveDelegates(_delegates[sender], _delegates[whirlpoolAddress], transferFeeAmount);\n                Whirlpool(whirlpoolAddress).addSurfReward(sender, transferFeeAmount);\n                emit Transfer(sender, whirlpoolAddress, transferFeeAmount);\n            }\n\n            tokensToTransfer = amount.sub(transferFeeAmount);\n\n            _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n\n            if (tokensToTransfer \u003e 0) {\n                _balances[recipient] = _balances[recipient].add(tokensToTransfer);\n                _moveDelegates(_delegates[sender], _delegates[recipient], tokensToTransfer);\n\n                // If the Whirlpool staking contract is the transfer recipient, addSurfReward gets called to keep things in sync\n                if (recipient == whirlpoolAddress) Whirlpool(whirlpoolAddress).addSurfReward(sender, tokensToTransfer);\n            }\n\n        }\n\n        emit Transfer(sender, recipient, tokensToTransfer);\n    }\n\n    // Internal function to determine if a SURF transfer is being sent or received by a whitelisted address\n    function _isWhitelistedTransfer(address _sender, address _recipient) internal view returns (bool) {\n        // The Whirlpool and Tito contracts are always whitelisted\n        return\n            _sender == whirlpoolAddress || _recipient == whirlpoolAddress ||\n            _sender == titoAddress || _recipient == titoAddress ||\n            senderWhitelist[_sender] == true || recipientWhitelist[_recipient] == true;\n    }\n\n    // Copied and modified from YAM code:\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol\n    // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol\n    // Which is copied and modified from COMPOUND:\n    // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol\n\n    /// @dev A record of each accounts delegate\n    mapping (address =\u003e address) internal _delegates;\n\n    /// @dev A checkpoint for marking number of votes from a given block\n    struct Checkpoint {\n        uint32 fromBlock;\n        uint256 votes;\n    }\n\n    /// @dev A record of votes checkpoints for each account, by index\n    mapping (address =\u003e mapping (uint32 =\u003e Checkpoint)) public checkpoints;\n\n    /// @dev The number of checkpoints for each account\n    mapping (address =\u003e uint32) public numCheckpoints;\n\n    /// @dev The EIP-712 typehash for the contract\u0027s domain\n    bytes32 public constant DOMAIN_TYPEHASH = keccak256(\"EIP712Domain(string name,uint256 chainId,address verifyingContract)\");\n\n    /// @dev The EIP-712 typehash for the delegation struct used by the contract\n    bytes32 public constant DELEGATION_TYPEHASH = keccak256(\"Delegation(address delegatee,uint256 nonce,uint256 expiry)\");\n\n    /// @dev A record of states for signing / validating signatures\n    mapping (address =\u003e uint) public nonces;\n\n      /// @dev An event thats emitted when an account changes its delegate\n    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);\n\n    /// @dev An event thats emitted when a delegate account\u0027s vote balance changes\n    event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);\n\n    /**\n     * @dev Delegate votes from `msg.sender` to `delegatee`\n     * @param delegator The address to get delegatee for\n     */\n    function delegates(address delegator) external view returns (address) {\n        return _delegates[delegator];\n    }\n\n   /**\n    * @dev Delegate votes from `msg.sender` to `delegatee`\n    * @param delegatee The address to delegate votes to\n    */\n    function delegate(address delegatee) external {\n        return _delegate(msg.sender, delegatee);\n    }\n\n    /**\n     * @dev Delegates votes from signatory to `delegatee`\n     * @param delegatee The address to delegate votes to\n     * @param nonce The contract state required to match the signature\n     * @param expiry The time at which to expire the signature\n     * @param v The recovery byte of the signature\n     * @param r Half of the ECDSA signature pair\n     * @param s Half of the ECDSA signature pair\n     */\n    function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) external {\n        bytes32 domainSeparator = keccak256(\n            abi.encode(\n                DOMAIN_TYPEHASH,\n                keccak256(bytes(name())),\n                getChainId(),\n                address(this)\n            )\n        );\n\n        bytes32 structHash = keccak256(\n            abi.encode(\n                DELEGATION_TYPEHASH,\n                delegatee,\n                nonce,\n                expiry\n            )\n        );\n\n        bytes32 digest = keccak256(\n            abi.encodePacked(\n                \"\\x19\\x01\",\n                domainSeparator,\n                structHash\n            )\n        );\n\n        address signatory = ecrecover(digest, v, r, s);\n        require(signatory != address(0), \"SURF::delegateBySig: invalid signature\");\n        require(nonce == nonces[signatory]++, \"SURF::delegateBySig: invalid nonce\");\n        require(now \u003c= expiry, \"SURF::delegateBySig: signature expired\");\n        return _delegate(signatory, delegatee);\n    }\n\n    /**\n     * @dev Gets the current votes balance for `account`\n     * @param account The address to get votes balance\n     * @return The number of current votes for `account`\n     */\n    function getCurrentVotes(address account) external view returns (uint256) {\n        uint32 nCheckpoints = numCheckpoints[account];\n        return nCheckpoints \u003e 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;\n    }\n\n    /**\n     * @dev Determine the prior number of votes for an account as of a block number\n     * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.\n     * @param account The address of the account to check\n     * @param blockNumber The block number to get the vote balance at\n     * @return The number of votes the account had as of the given block\n     */\n    function getPriorVotes(address account, uint blockNumber) external view returns (uint256) {\n        require(blockNumber \u003c block.number, \"SURF::getPriorVotes: not yet determined\");\n\n        uint32 nCheckpoints = numCheckpoints[account];\n        if (nCheckpoints == 0) {\n            return 0;\n        }\n\n        // First check most recent balance\n        if (checkpoints[account][nCheckpoints - 1].fromBlock \u003c= blockNumber) {\n            return checkpoints[account][nCheckpoints - 1].votes;\n        }\n\n        // Next check implicit zero balance\n        if (checkpoints[account][0].fromBlock \u003e blockNumber) {\n            return 0;\n        }\n\n        uint32 lower = 0;\n        uint32 upper = nCheckpoints - 1;\n        while (upper \u003e lower) {\n            uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow\n            Checkpoint memory cp = checkpoints[account][center];\n            if (cp.fromBlock == blockNumber) {\n                return cp.votes;\n            } else if (cp.fromBlock \u003c blockNumber) {\n                lower = center;\n            } else {\n                upper = center - 1;\n            }\n        }\n        return checkpoints[account][lower].votes;\n    }\n\n    function _delegate(address delegator, address delegatee) internal {\n        address currentDelegate = _delegates[delegator];\n        uint256 delegatorBalance = balanceOf(delegator); // balance of underlying SURFs (not scaled);\n        _delegates[delegator] = delegatee;\n\n        emit DelegateChanged(delegator, currentDelegate, delegatee);\n\n        _moveDelegates(currentDelegate, delegatee, delegatorBalance);\n    }\n\n    function _moveDelegates(address srcRep, address dstRep, uint256 amount) internal {\n        if (srcRep != dstRep \u0026\u0026 amount \u003e 0) {\n            if (srcRep != address(0)) {\n                // decrease old representative\n                uint32 srcRepNum = numCheckpoints[srcRep];\n                uint256 srcRepOld = srcRepNum \u003e 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;\n                uint256 srcRepNew = srcRepOld.sub(amount);\n                _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);\n            }\n\n            if (dstRep != address(0)) {\n                // increase new representative\n                uint32 dstRepNum = numCheckpoints[dstRep];\n                uint256 dstRepOld = dstRepNum \u003e 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;\n                uint256 dstRepNew = dstRepOld.add(amount);\n                _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);\n            }\n        }\n    }\n\n    function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint256 oldVotes, uint256 newVotes) internal {\n        uint32 blockNumber = safe32(block.number, \"SURF::_writeCheckpoint: block number exceeds 32 bits\");\n\n        if (nCheckpoints \u003e 0 \u0026\u0026 checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {\n            checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;\n        } else {\n            checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);\n            numCheckpoints[delegatee] = nCheckpoints + 1;\n        }\n\n        emit DelegateVotesChanged(delegatee, oldVotes, newVotes);\n    }\n\n    function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {\n        require(n \u003c 2**32, errorMessage);\n        return uint32(n);\n    }\n\n    function getChainId() internal pure returns (uint) {\n        uint256 chainId;\n        assembly { chainId := chainid() }\n        return chainId;\n    }\n}"},"Tito.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./SafeERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./IUniswapV2Router02.sol\u0027;\nimport \u0027./UniStakingInterfaces.sol\u0027;\nimport \u0027./SURF.sol\u0027;\nimport \u0027./Whirlpool.sol\u0027;\n\n// Tito is the master of SURF. He can make SURF, is a fair guy, and a great instructor.\ncontract Tito is Ownable {\n    using SafeMath for uint256;\n    using SafeERC20 for IERC20;\n\n    // Info of each user.\n    struct UserInfo {\n        uint256 staked; // How many LP tokens the user has provided.\n        uint256 rewardDebt; // Reward debt. See explanation below.\n        uint256 uniRewardDebt; // UNI staking reward debt. See explanation below.\n        uint256 claimed; // Tracks the amount of SURF claimed by the user.\n        uint256 uniClaimed; // Tracks the amount of UNI claimed by the user.\n    }\n\n    // Info of each pool.\n    struct PoolInfo {\n        IERC20 token; // Address of token contract.\n        IERC20 lpToken; // Address of LP token contract.\n        uint256 apr; // Fixed APR for the pool. Determines how many SURFs to distribute per block.\n        uint256 lastSurfRewardBlock; // Last block number that SURF rewards were distributed.\n        uint256 accSurfPerShare; // Accumulated SURFs per share, times 1e12. See below.\n        uint256 accUniPerShare; // Accumulated UNIs per share, times 1e12. See below.\n        address uniStakeContract; // Address of UNI staking contract (if applicable).\n    }\n\n    // We do some fancy math here. Basically, any point in time, the amount of SURFs\n    // entitled to a user but is pending to be distributed is:\n    //\n    //   pending reward = (user.staked * pool.accSurfPerShare) - user.rewardDebt\n    //\n    // Whenever a user deposits or withdraws LP tokens to a pool. Here\u0027s what happens:\n    //   1. The pool\u0027s `accSurfPerShare` (and `lastSurfRewardBlock`) gets updated.\n    //   2. User receives the pending reward sent to his/her address.\n    //   3. User\u0027s `staked` amount gets updated.\n    //   4. User\u0027s `rewardDebt` gets updated.\n\n    // The SURF TOKEN!\n    SURF public surf;\n    // The address of the SURF-ETH Uniswap pool\n    address public surfPoolAddress;\n     // The Whirlpool staking contract\n    Whirlpool public whirlpool;\n    // The Uniswap v2 Router\n    IUniswapV2Router02 internal uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);\n    // The UNI Staking Rewards Factory\n    StakingRewardsFactory internal uniStakingFactory = StakingRewardsFactory(0x3032Ab3Fa8C01d786D29dAdE018d7f2017918e12);\n    // The UNI Token\n    IERC20 internal uniToken = IERC20(0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984);\n    // The WETH Token\n    IERC20 internal weth;\n    // Dev address\n    address payable public devAddress;\n\n    // Info of each pool.\n    PoolInfo[] public poolInfo;\n    mapping(address =\u003e bool) public existingPools;\n    // Info of each user that stakes LP tokens.\n    mapping (uint256 =\u003e mapping (address =\u003e UserInfo)) public userInfo;\n    // Mapping of whitelisted contracts so that certain contracts like the Aegis pool can interact with the Tito contract\n    mapping(address =\u003e bool) public contractWhitelist;\n    // The block number when SURF mining starts.\n    uint256 public startBlock;\n    // Becomes true once the SURF-ETH Uniswap is created (no sooner than 500 blocks after launch)\n    bool public surfPoolActive = false;\n    // The staking fees collected during the first 500 blocks will seed the SURF-ETH Uniswap pool\n    uint256 public initialSurfPoolETH  = 0;\n    // 5% of every deposit into any secondary pool (not SURF-ETH) will be converted to SURF (on Uniswap) and sent to the Whirlpool staking contract which becomes active and starts distributing the accumulated SURF to stakers once the max supply is hit\n    uint256 public surfSentToWhirlpool = 0;\n    // The amount of ETH donated to the SURF community by partner projects\n    uint256 public donatedETH = 0;\n    // Certain partner projects need to donate 25 ETH to the SURF community to get a beach\n    uint256 internal constant minimumDonationAmount = 25 * 10**18;\n    // Mapping of addresses that donated ETH on behalf of a partner project\n    mapping(address =\u003e address) internal donaters;\n    // Mapping of the size of donations from partner projects\n    mapping(address =\u003e uint256) internal donations;\n    // Approximate number of blocks per year - assumes 13 second blocks\n    uint256 internal constant APPROX_BLOCKS_PER_YEAR  = uint256(uint256(365 days) / uint256(13 seconds));\n    // The default APR for each pool will be 1,000%\n    uint256 internal constant DEFAULT_APR = 1000;\n    // There will be a 1000 block Soft Launch in which SURF is minted to each pool at a static rate to make the start as fair as possible\n    uint256 internal constant SOFT_LAUNCH_DURATION = 1000;\n    // During the Soft Launch, all pools except for the SURF-ETH pool will mint 40 SURF per block. Once it\u0027s activated, the SURF-ETH pool will mint the same amount of SURF per block as all of the other pools combined until the end of the Soft Launch\n    uint256 internal constant SOFT_LAUNCH_SURF_PER_BLOCK = 40 * 10**18;\n\n    event Deposit(address indexed user, uint256 indexed pid, uint256 amount);\n    event Claim(address indexed user, uint256 indexed pid, uint256 surfAmount, uint256 uniAmount);\n    event ClaimAll(address indexed user, uint256 surfAmount, uint256 uniAmount);\n    event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);\n    event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);\n    event SurfBuyback(address indexed user, uint256 ethSpentOnSurf, uint256 surfBought);\n    event SurfPoolActive(address indexed user, uint256 surfLiquidity, uint256 ethLiquidity);\n\n    constructor(\n        SURF _surf,\n        address payable _devAddress,\n        uint256 _startBlock\n    ) public {\n        surf = _surf;\n        devAddress = _devAddress;\n        startBlock = _startBlock;\n        weth = IERC20(uniswapRouter.WETH());\n\n        // Calculate the address the SURF-ETH Uniswap pool will exist at\n        address uniswapfactoryAddress = uniswapRouter.factory();\n        address surfAddress = address(surf);\n        address wethAddress = address(weth);\n\n        // token0 must be strictly less than token1 by sort order to determine the correct address\n        (address token0, address token1) = surfAddress \u003c wethAddress ? (surfAddress, wethAddress) : (wethAddress, surfAddress);\n\n        surfPoolAddress = address(uint(keccak256(abi.encodePacked(\n            hex\u0027ff\u0027,\n            uniswapfactoryAddress,\n            keccak256(abi.encodePacked(token0, token1)),\n            hex\u002796e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f\u0027\n        ))));\n\n        _addInitialPools();\n    }\n\n    receive() external payable {}\n\n    // Internal function to add a new LP Token pool\n    function _addPool(address _token, address _lpToken) internal {\n\n        uint256 apr = DEFAULT_APR;\n        if (_token == address(surf)) apr = apr * 5;\n\n        uint256 lastSurfRewardBlock = block.number \u003e startBlock ? block.number : startBlock;\n\n        poolInfo.push(\n            PoolInfo({\n                token: IERC20(_token),\n                lpToken: IERC20(_lpToken),\n                apr: apr,\n                lastSurfRewardBlock: lastSurfRewardBlock,\n                accSurfPerShare: 0,\n                accUniPerShare: 0,\n                uniStakeContract: address(0)\n            })\n        );\n\n        existingPools[_lpToken] = true;\n    }\n\n    // Internal function that adds all of the pools that will be available at launch. Called by the constructor\n    function _addInitialPools() internal {\n\n        _addPool(address(surf), surfPoolAddress); // SURF-ETH\n\n        _addPool(0xdAC17F958D2ee523a2206206994597C13D831ec7, 0x0d4a11d5EEaaC28EC3F61d100daF4d40471f1852); // ETH-USDT\n        _addPool(0x6B175474E89094C44Da98b954EedeAC495271d0F, 0xA478c2975Ab1Ea89e8196811F51A7B7Ade33eB11); // DAI-ETH\n        _addPool(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, 0xB4e16d0168e52d35CaCD2c6185b44281Ec28C9Dc); // USDC-ETH\n        _addPool(0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599, 0xBb2b8038a1640196FbE3e38816F3e67Cba72D940); // WBTC-ETH\n        _addPool(0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, 0xd3d2E2692501A5c9Ca623199D38826e513033a17); // UNI-ETH\n        _addPool(0x514910771AF9Ca656af840dff83E8264EcF986CA, 0xa2107FA5B38d9bbd2C461D6EDf11B11A50F6b974); // LINK-ETH\n        _addPool(0x7Fc66500c84A76Ad7e9c93437bFc5Ac33E2DDaE9, 0xDFC14d2Af169B0D36C4EFF567Ada9b2E0CAE044f); // AAVE-ETH\n        _addPool(0xC011a73ee8576Fb46F5E1c5751cA3B9Fe0af2a6F, 0x43AE24960e5534731Fc831386c07755A2dc33D47); // SNX-ETH\n        _addPool(0x9f8F72aA9304c8B593d555F12eF6589cC3A579A2, 0xC2aDdA861F89bBB333c90c492cB837741916A225); // MKR-ETH\n        _addPool(0xc00e94Cb662C3520282E6f5717214004A7f26888, 0xCFfDdeD873554F362Ac02f8Fb1f02E5ada10516f); // COMP-ETH\n        _addPool(0x0bc529c00C6401aEF6D220BE8C6Ea1667F6Ad93e, 0x2fDbAdf3C4D5A8666Bc06645B8358ab803996E28); // YFI-ETH\n        _addPool(0xba100000625a3754423978a60c9317c58a424e3D, 0xA70d458A4d9Bc0e6571565faee18a48dA5c0D593); // BAL-ETH\n        _addPool(0x1494CA1F11D487c2bBe4543E90080AeBa4BA3C2b, 0x4d5ef58aAc27d99935E5b6B4A6778ff292059991); // DPI-ETH\n        _addPool(0xD46bA6D942050d489DBd938a2C909A5d5039A161, 0xc5be99A02C6857f9Eac67BbCE58DF5572498F40c); // AMPL-ETH\n        _addPool(0x2b591e99afE9f32eAA6214f7B7629768c40Eeb39, 0x55D5c232D921B9eAA6b37b5845E439aCD04b4DBa); // HEX-ETH\n        _addPool(0x93ED3FBe21207Ec2E8f2d3c3de6e058Cb73Bc04d, 0x343FD171caf4F0287aE6b87D75A8964Dc44516Ab); // PNK-ETH\n        _addPool(0x429881672B9AE42b8EbA0E26cD9C73711b891Ca5, 0xdc98556Ce24f007A5eF6dC1CE96322d65832A819); // PICKLE-ETH\n        _addPool(0x84294FC9710e1252d407d3D80A84bC39001bd4A8, 0x0C5136B5d184379fa15bcA330784f2d5c226Fe96); // NUTS-ETH\n        _addPool(0x821144518dfE9e7b44fCF4d0824e15e8390d4637, 0x490B5B2489eeFC4106C69743F657e3c4A2870aC5); // ATIS-ETH\n        _addPool(0xB9464ef80880c5aeA54C7324c0b8Dd6ca6d05A90, 0xa8D0f6769AB020877f262D8Cd747c188D9097d7E); // LOCK-ETH\n        _addPool(0x926dbD499d701C61eABe2d576e770ECCF9c7F4F3, 0xC7c0EDf0b5f89eff96aF0E31643Bd588ad63Ea23); // aDAO-ETH\n        _addPool(0x3A9FfF453d50D4Ac52A6890647b823379ba36B9E, 0x260E069deAd76baAC587B5141bB606Ef8b9Bab6c); // SHUF-ETH\n        _addPool(0x9720Bcf5a92542D4e286792fc978B63a09731CF0, 0x08538213596fB2c392e9c5d4935ad37645600a57); // OTBC-ETH\n        _addPool(0xEEF9f339514298C6A857EfCfC1A762aF84438dEE, 0x23d15EDceb5B5B3A23347Fa425846DE80a2E8e5C); // HEZ-ETH\n\n        // These beaches will be manually added after their teams make the 25 ETH donation\n        // _addPool(0x6F87D756DAf0503d08Eb8993686c7Fc01Dc44fB1, 0xd2E0C4928789e5DB620e53af29F5fC7bcA262635); // TRADE-ETH\n        \n    }\n\n    // Get the pending SURFs for a user from 1 pool\n    function _pendingSurf(uint256 _pid, address _user) internal view returns (uint256) {\n        if (_pid == 0 \u0026\u0026 surfPoolActive != true) return 0;\n\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo memory user = userInfo[_pid][_user];\n        uint256 accSurfPerShare = pool.accSurfPerShare;\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        if (block.number \u003e pool.lastSurfRewardBlock \u0026\u0026 lpSupply != 0) {\n            uint256 surfReward = _calculateSurfReward(_pid, lpSupply);\n\n            // Make sure that surfReward won\u0027t push the total supply of SURF past surf.MAX_SUPPLY()\n            uint256 surfTotalSupply = surf.totalSupply();\n            if (surfTotalSupply.add(surfReward) \u003e= surf.MAX_SUPPLY()) {\n                surfReward = surf.MAX_SUPPLY().sub(surfTotalSupply);\n            }\n\n            accSurfPerShare = accSurfPerShare.add(surfReward.mul(1e12).div(lpSupply));\n        }\n\n        return user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n    }\n\n    // Get the pending UNIs for a user from 1 pool\n    function _pendingUni(uint256 _pid, address _user) internal view returns (uint256) {\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo memory user = userInfo[_pid][_user];\n        uint256 accUniPerShare = pool.accUniPerShare;\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        if (pool.uniStakeContract != address(0) \u0026\u0026 lpSupply != 0) {\n            uint256 uniReward = IStakingRewards(pool.uniStakeContract).earned(address(this));\n            accUniPerShare = accUniPerShare.add(uniReward.mul(1e12).div(lpSupply));\n        }\n        return user.staked.mul(accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n    }\n\n    // Calculate the current surfReward for a specific pool\n    function _calculateSurfReward(uint256 _pid, uint256 _lpSupply) internal view returns (uint256 surfReward) {\n        \n        if (surf.maxSupplyHit() != true) {\n\n            PoolInfo memory pool = poolInfo[_pid];\n\n            uint256 multiplier = block.number - pool.lastSurfRewardBlock;\n                \n            // There will be a 1000 block Soft Launch where SURF is minted at a static rate to make things as fair as possible\n            if (block.number \u003c startBlock + SOFT_LAUNCH_DURATION) {\n\n                // The SURF-ETH pool isn\u0027t active until the Uniswap pool is created, which can\u0027t happen until at least 500 blocks have passed. Once active, it mints 1000 SURF per block (the same amount of SURF per block as all of the other pools combined) until the Soft Launch ends\n                if (_pid != 0) {\n                    // For the first 1000 blocks, give 40 SURF per block to all other pools that have staked LP tokens\n                    surfReward = multiplier * SOFT_LAUNCH_SURF_PER_BLOCK;\n                } else if (surfPoolActive == true) {\n                    surfReward = multiplier * 25 * SOFT_LAUNCH_SURF_PER_BLOCK;\n                }\n            \n            } else if (_pid != 0 \u0026\u0026 surfPoolActive != true) {\n                // Keep minting 40 tokens per block since the Soft Launch is over but the SURF-ETH pool still isn\u0027t active (would only be due to no one calling the activateSurfPool function)\n                surfReward = multiplier * SOFT_LAUNCH_SURF_PER_BLOCK;\n            } else if (surfPoolActive == true) { \n                // Afterwards, give surfReward based on the pool\u0027s fixed APR.\n                // Fast low gas cost way of calculating prices since this can be called every block.\n                uint256 surfPrice = _getSurfPrice();\n                uint256 lpTokenPrice = 10**18 * 2 * weth.balanceOf(address(pool.lpToken)) / pool.lpToken.totalSupply(); \n                uint256 scaledTotalLiquidityValue = _lpSupply * lpTokenPrice;\n                surfReward = multiplier * ((pool.apr * scaledTotalLiquidityValue / surfPrice) / APPROX_BLOCKS_PER_YEAR) / 100;\n            }\n\n        }\n\n    }\n\n    function poolLength() external view returns (uint256) {\n        return poolInfo.length;\n    }\n\n    // Internal view function to get all of the stored data for a single pool\n    function _getPoolData(uint256 _pid) internal view returns (address, address, bool, uint256, uint256, uint256, uint256) {\n        PoolInfo memory pool = poolInfo[_pid];\n        return (address(pool.token), address(pool.lpToken), pool.uniStakeContract != address(0), pool.apr, pool.lastSurfRewardBlock, pool.accSurfPerShare, pool.accUniPerShare);\n    }\n\n    // View function to see all of the stored data for every pool on the frontend\n    function _getAllPoolData() internal view returns (address[] memory, address[] memory, bool[] memory, uint[] memory, uint[] memory, uint[2][] memory) {\n        uint256 length = poolInfo.length;\n        address[] memory tokenData = new address[](length);\n        address[] memory lpTokenData = new address[](length);\n        bool[] memory isUniData = new bool[](length);\n        uint[] memory aprData = new uint[](length);\n        uint[] memory lastSurfRewardBlockData = new uint[](length);\n        uint[2][] memory accTokensPerShareData = new uint[2][](length);\n\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            (tokenData[pid], lpTokenData[pid], isUniData[pid], aprData[pid], lastSurfRewardBlockData[pid], accTokensPerShareData[pid][0], accTokensPerShareData[pid][1]) = _getPoolData(pid);\n        }\n\n        return (tokenData, lpTokenData, isUniData, aprData, lastSurfRewardBlockData, accTokensPerShareData);\n    }\n\n    // Internal view function to get all of the extra data for a single pool\n    function _getPoolMetadataFor(uint256 _pid, address _user, uint256 _surfPrice) internal view returns (uint[17] memory poolMetadata) {\n        PoolInfo memory pool = poolInfo[_pid];\n\n        uint256 totalSupply;\n        uint256 totalLPSupply;\n        uint256 stakedLPSupply;\n        uint256 tokenPrice;\n        uint256 lpTokenPrice;\n        uint256 totalLiquidityValue;\n        uint256 surfPerBlock;\n\n        if (_pid != 0 || surfPoolActive == true) {\n            totalSupply = pool.token.totalSupply();\n            totalLPSupply = pool.lpToken.totalSupply();\n            stakedLPSupply = _getPoolSupply(_pid);\n\n            tokenPrice = 10**uint256(pool.token.decimals()) * weth.balanceOf(address(pool.lpToken)) / pool.token.balanceOf(address(pool.lpToken));\n            lpTokenPrice = 10**18 * 2 * weth.balanceOf(address(pool.lpToken)) / totalLPSupply; \n            totalLiquidityValue = stakedLPSupply * lpTokenPrice / 1e18;\n        }\n\n        // Only calculate with fixed apr after the Soft Launch\n        if (block.number \u003e= startBlock + SOFT_LAUNCH_DURATION) {\n            surfPerBlock = ((pool.apr * 1e18 * totalLiquidityValue / _surfPrice) / APPROX_BLOCKS_PER_YEAR) / 100;\n        } else {\n            if (_pid != 0) {\n                surfPerBlock = SOFT_LAUNCH_SURF_PER_BLOCK;\n            } else if (surfPoolActive == true) {\n                surfPerBlock = 25 * SOFT_LAUNCH_SURF_PER_BLOCK;\n            }\n        }\n\n        // Global pool information\n        poolMetadata[0] = totalSupply;\n        poolMetadata[1] = totalLPSupply;\n        poolMetadata[2] = stakedLPSupply;\n        poolMetadata[3] = tokenPrice;\n        poolMetadata[4] = lpTokenPrice;\n        poolMetadata[5] = totalLiquidityValue;\n        poolMetadata[6] = surfPerBlock;\n        poolMetadata[7] = pool.token.decimals();\n\n        // User pool information\n        if (_pid != 0 || surfPoolActive == true) {\n            UserInfo memory _userInfo = userInfo[_pid][_user];\n            poolMetadata[8] = pool.token.balanceOf(_user);\n            poolMetadata[9] = pool.token.allowance(_user, address(this));\n            poolMetadata[10] = pool.lpToken.balanceOf(_user);\n            poolMetadata[11] = pool.lpToken.allowance(_user, address(this));\n            poolMetadata[12] = _userInfo.staked;\n            poolMetadata[13] = _pendingSurf(_pid, _user);\n            poolMetadata[14] = _pendingUni(_pid, _user);\n            poolMetadata[15] = _userInfo.claimed;\n            poolMetadata[16] = _userInfo.uniClaimed;\n        }\n    }\n\n    // View function to see all of the extra pool data (token prices, total staked supply, total liquidity value, etc) on the frontend\n    function _getAllPoolMetadataFor(address _user) internal view returns (uint[17][] memory allMetadata) {\n        uint256 length = poolInfo.length;\n\n        // Extra data for the frontend\n        allMetadata = new uint[17][](length);\n\n        // We\u0027ll need the current SURF price to make our calculations\n        uint256 surfPrice = _getSurfPrice();\n\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            allMetadata[pid] = _getPoolMetadataFor(pid, _user, surfPrice);\n        }\n    }\n\n    // View function to see all of the data for all pools on the frontend\n    function getAllPoolInfoFor(address _user) external view returns (address[] memory tokens, address[] memory lpTokens, bool[] memory isUnis, uint[] memory aprs, uint[] memory lastSurfRewardBlocks, uint[2][] memory accTokensPerShares, uint[17][] memory metadatas) {\n        (tokens, lpTokens, isUnis, aprs, lastSurfRewardBlocks, accTokensPerShares) = _getAllPoolData();\n        metadatas = _getAllPoolMetadataFor(_user);\n    }\n\n    // Internal view function to get the current price of SURF on Uniswap\n    function _getSurfPrice() internal view returns (uint256 surfPrice) {\n        uint256 surfBalance = surf.balanceOf(surfPoolAddress);\n        if (surfBalance \u003e 0) {\n            surfPrice = 10**18 * weth.balanceOf(surfPoolAddress) / surfBalance;\n        }\n    }\n\n    // View function to show all relevant platform info on the frontend\n    function getAllInfoFor(address _user) external view returns (bool poolActive, uint256[8] memory info) {\n        poolActive = surfPoolActive;\n        info[0] = blocksUntilLaunch();\n        info[1] = blocksUntilSurfPoolCanBeActivated();\n        info[2] = blocksUntilSoftLaunchEnds();\n        info[3] = surf.totalSupply();\n        info[4] = _getSurfPrice();\n        if (surfPoolActive) {\n            info[5] = IERC20(surfPoolAddress).balanceOf(address(surf));\n        }\n        info[6] = surfSentToWhirlpool;\n        info[7] = surf.balanceOf(_user);\n    }\n\n    // View function to see the number of blocks remaining until launch on the frontend\n    function blocksUntilLaunch() public view returns (uint256) {\n        if (block.number \u003e= startBlock) return 0;\n        else return startBlock.sub(block.number);\n    }\n\n    // View function to see the number of blocks remaining until the SURF pool can be activated on the frontend\n    function blocksUntilSurfPoolCanBeActivated() public view returns (uint256) {\n        uint256 surfPoolActivationBlock = startBlock + SOFT_LAUNCH_DURATION.div(2);\n        if (block.number \u003e= surfPoolActivationBlock) return 0;\n        else return surfPoolActivationBlock.sub(block.number);\n    }\n\n    // View function to see the number of blocks remaining until the Soft Launch ends on the frontend\n    function blocksUntilSoftLaunchEnds() public view returns (uint256) {\n        uint256 softLaunchEndBlock = startBlock + SOFT_LAUNCH_DURATION;\n        if (block.number \u003e= softLaunchEndBlock) return 0;\n        else return softLaunchEndBlock.sub(block.number);\n    }\n\n    // Update reward variables for all pools. Be careful of gas spending!\n    function massUpdatePools() public {\n        uint256 length = poolInfo.length;\n        for (uint256 pid = (surfPoolActive == true ? 0 : 1); pid \u003c length; ++pid) {\n            updatePool(pid);\n        }\n    }\n\n    // Update reward variables of the given pool to be up-to-date.\n    function updatePool(uint256 _pid) public {\n        require(msg.sender == tx.origin || msg.sender == owner() || contractWhitelist[msg.sender] == true, \"no contracts\"); // Prevent flash loan attacks that manipulate prices.\n        \n        PoolInfo storage pool = poolInfo[_pid];\n        uint256 lpSupply = _getPoolSupply(_pid);\n\n        // Handle the UNI staking rewards contract for the LP token if one exists.\n        // The SURF-ETH pool would break by using the UNI staking rewards contract if one is made for it so it will be ignored\n        if (_pid != 0) {\n            // Check to see if the LP token has a UNI staking rewards contract to forward deposits to so that users can earn both SURF and UNI\n            if (pool.uniStakeContract == address(0)) {\n                (address uniStakeContract,) = uniStakingFactory.stakingRewardsInfoByStakingToken(address(pool.lpToken));\n\n                // If a UNI staking rewards contract exists then transfer all of the LP tokens to it to start earning UNI\n                if (uniStakeContract != address(0)) {\n                    pool.uniStakeContract = uniStakeContract;\n\n                    if (lpSupply \u003e 0) {\n                        pool.lpToken.safeApprove(uniStakeContract, 0);\n                        pool.lpToken.safeApprove(uniStakeContract, lpSupply);\n                        IStakingRewards(pool.uniStakeContract).stake(lpSupply);\n                    }\n                }\n            }\n\n            // A UNI staking rewards contract for this LP token is being used so get any pending UNI rewards\n            if (pool.uniStakeContract != address(0)) {\n                uint256 pendingUniTokens = IStakingRewards(pool.uniStakeContract).earned(address(this));\n                if (pendingUniTokens \u003e 0) {\n                    uint256 uniBalanceBefore = uniToken.balanceOf(address(this));\n                    IStakingRewards(pool.uniStakeContract).getReward();\n                    uint256 uniBalanceAfter = uniToken.balanceOf(address(this));\n                    pendingUniTokens = uniBalanceAfter.sub(uniBalanceBefore);\n                    pool.accUniPerShare = pool.accUniPerShare.add(pendingUniTokens.mul(1e12).div(lpSupply));\n                }\n            }\n        }\n\n        // Only update the pool if the max SURF supply hasn\u0027t been hit\n        if (surf.maxSupplyHit() != true) {\n            \n            if ((block.number \u003c= pool.lastSurfRewardBlock) || (_pid == 0 \u0026\u0026 surfPoolActive != true)) {\n                return;\n            }\n            if (lpSupply == 0) {\n                pool.lastSurfRewardBlock = block.number;\n                return;\n            }\n\n            uint256 surfReward = _calculateSurfReward(_pid, lpSupply);\n\n            // Make sure that surfReward won\u0027t push the total supply of SURF past surf.MAX_SUPPLY()\n            uint256 surfTotalSupply = surf.totalSupply();\n            if (surfTotalSupply.add(surfReward) \u003e= surf.MAX_SUPPLY()) {\n                surfReward = surf.MAX_SUPPLY().sub(surfTotalSupply);\n            }\n\n            // surf.mint(devAddress, surfReward.div(10)); Not minting 10% to the devs like Sushi, Sashimi, and Takeout do\n\n            if (surfReward \u003e 0) {\n                surf.mint(address(this), surfReward);\n                pool.accSurfPerShare = pool.accSurfPerShare.add(surfReward.mul(1e12).div(lpSupply));\n                pool.lastSurfRewardBlock = block.number;\n            }\n\n            if (surf.maxSupplyHit() == true) {\n                whirlpool.activate();\n            }\n        }\n    }\n\n    // Internal view function to get the amount of LP tokens staked in the specified pool\n    function _getPoolSupply(uint256 _pid) internal view returns (uint256 lpSupply) {\n        PoolInfo memory pool = poolInfo[_pid];\n\n        if (pool.uniStakeContract != address(0)) {\n            lpSupply = IStakingRewards(pool.uniStakeContract).balanceOf(address(this));\n        } else {\n            lpSupply = pool.lpToken.balanceOf(address(this));\n        }\n    }\n\n    // Deposits LP tokens in the specified pool to start earning the user SURF\n    function deposit(uint256 _pid, uint256 _amount) external {\n        depositFor(_pid, msg.sender, _amount);\n    }\n\n    // Deposits LP tokens in the specified pool on behalf of another user\n    function depositFor(uint256 _pid, address _user, uint256 _amount) public {\n        require(msg.sender == tx.origin || contractWhitelist[msg.sender] == true, \"no contracts\");\n        require(surf.maxSupplyHit() != true, \"pools closed\");\n        require(_pid != 0 || surfPoolActive == true, \"surf pool not active\");\n        require(_amount \u003e 0, \"deposit something\");\n\n        updatePool(_pid);\n\n        PoolInfo storage pool = poolInfo[_pid];\n        UserInfo storage user = userInfo[_pid][_user];\n\n        // The sender needs to give approval to the Tito contract for the specified amount of the LP token first\n        pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);\n\n        // Claim any pending SURF and UNI\n        _claimRewardsFromPool(_pid, _user);\n        \n        // Each pool has a 10% staking fee. If staking in the SURF-ETH pool, 100% of the fee gets permanently locked in the SURF contract (gives SURF liquidity forever).\n        // If staking in any other pool, 50% of the fee is used to buyback SURF which is sent to the Whirlpool staking contract where it will start getting distributed to stakers after the max supply is hit, and 50% goes to the team.\n        // The team is never minted or rewarded SURF for any reason to keep things as fair as possible.\n        uint256 stakingFeeAmount = _amount.div(10);\n        uint256 remainingUserAmount = _amount.sub(stakingFeeAmount);\n\n        // If a UNI staking rewards contract is available, use it\n        if (pool.uniStakeContract != address(0)) {\n            pool.lpToken.safeApprove(pool.uniStakeContract, 0);\n            pool.lpToken.safeApprove(pool.uniStakeContract, remainingUserAmount);\n            IStakingRewards(pool.uniStakeContract).stake(remainingUserAmount);\n        }\n\n        // The user is depositing to the SURF-ETH pool so permanently lock all of the LP tokens from the staking fee in the SURF contract\n        if (_pid == 0) {\n            pool.lpToken.transfer(address(surf), stakingFeeAmount);\n        } else {\n            uint256 ethBalanceBeforeSwap = address(this).balance;\n\n            // Remove the liquidity from the pool\n            uint256 deadline = block.timestamp + 5 minutes;\n            pool.lpToken.safeApprove(address(uniswapRouter), 0);\n            pool.lpToken.safeApprove(address(uniswapRouter), stakingFeeAmount);\n            uniswapRouter.removeLiquidityETHSupportingFeeOnTransferTokens(address(pool.token), stakingFeeAmount, 0, 0, address(this), deadline);\n\n            // Swap the ERC-20 token for ETH\n            uint256 tokensToSwap = pool.token.balanceOf(address(this));\n            require(tokensToSwap \u003e 0, \"bad token swap\");\n            address[] memory poolPath = new address[](2);\n            poolPath[0] = address(pool.token);\n            poolPath[1] = address(weth);\n            pool.token.safeApprove(address(uniswapRouter), 0);\n            pool.token.safeApprove(address(uniswapRouter), tokensToSwap);\n            uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(tokensToSwap, 0, poolPath, address(this), deadline);\n\n            uint256 ethBalanceAfterSwap = address(this).balance;\n            uint256 ethReceivedFromStakingFee;\n            uint256 teamFeeAmount;\n\n            // If surfPoolActive == true then perform a buyback of SURF using all of the ETH in the contract and then send it to the Whirlpool staking contract. Otherwise, the ETH will be used to seed the initial liquidity in the SURF-ETH Uniswap pool when activateSurfPool is called\n            if (surfPoolActive == true) {\n                require(ethBalanceAfterSwap \u003e 0, \"bad eth swap\");\n\n                teamFeeAmount = ethBalanceAfterSwap.div(2);\n                ethReceivedFromStakingFee = ethBalanceAfterSwap.sub(teamFeeAmount);\n\n                // The SURF-ETH pool is active, so let\u0027s use the ETH to buyback SURF and send it to the Whirlpool staking contract\n                uint256 surfBought = _buySurf(ethReceivedFromStakingFee);\n\n                // Send the SURF rewards to the Whirlpool staking contract\n                surfSentToWhirlpool += surfBought;\n                _safeSurfTransfer(address(whirlpool), surfBought);\n            } else {\n                ethReceivedFromStakingFee = ethBalanceAfterSwap.sub(ethBalanceBeforeSwap);\n                require(ethReceivedFromStakingFee \u003e 0, \"bad eth swap\");\n\n                teamFeeAmount = ethReceivedFromStakingFee.div(2);\n            }\n\n            if (teamFeeAmount \u003e 0) devAddress.transfer(teamFeeAmount);\n        }\n\n        // Add the remaining amount to the user\u0027s staked balance\n        uint256 _currentRewardDebt = 0;\n        uint256 _currentUniRewardDebt = 0;\n        if (surfPoolActive != true) {\n            _currentRewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(user.rewardDebt);\n            _currentUniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n        }\n        user.staked = user.staked.add(remainingUserAmount);\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(_currentRewardDebt);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12).sub(_currentUniRewardDebt);\n\n        emit Deposit(_user, _pid, _amount);\n    }\n\n    // Internal function that buys back SURF with the amount of ETH specified\n    function _buySurf(uint256 _amount) internal returns (uint256 surfBought) {\n        uint256 ethBalance = address(this).balance;\n        if (_amount \u003e ethBalance) _amount = ethBalance;\n        if (_amount \u003e 0) {\n            uint256 deadline = block.timestamp + 5 minutes;\n            address[] memory surfPath = new address[](2);\n            surfPath[0] = address(weth);\n            surfPath[1] = address(surf);\n            uint256[] memory amounts = uniswapRouter.swapExactETHForTokens{value: _amount}(0, surfPath, address(this), deadline);\n            surfBought = amounts[1];\n        }\n        if (surfBought \u003e 0) emit SurfBuyback(msg.sender, _amount, surfBought);\n    }\n\n    // Internal function to claim earned SURF and UNI from Tito. Claiming won\u0027t work until surfPoolActive == true\n    function _claimRewardsFromPool(uint256 _pid, address _user) internal {\n        PoolInfo memory pool = poolInfo[_pid];\n        UserInfo storage user = userInfo[_pid][_user];\n\n        if (surfPoolActive != true || user.staked == 0) return;\n\n        uint256 userUniPending = user.staked.mul(pool.accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n        uint256 uniBalance = uniToken.balanceOf(address(this));\n        if (userUniPending \u003e uniBalance) userUniPending = uniBalance;\n        if (userUniPending \u003e 0) {\n            user.uniClaimed += userUniPending;\n            uniToken.transfer(_user, userUniPending);\n        }\n\n        uint256 userSurfPending = user.staked.mul(pool.accSurfPerShare).div(1e12).sub(user.rewardDebt);\n        if (userSurfPending \u003e 0) {\n            user.claimed += userSurfPending;\n            _safeSurfTransfer(_user, userSurfPending);\n        }\n\n        if (userSurfPending \u003e 0 || userUniPending \u003e 0) {\n            emit Claim(_user, _pid, userSurfPending, userUniPending);\n        }\n    }\n\n    // Claim all earned SURF and UNI from a single pool. Claiming won\u0027t work until surfPoolActive == true\n    function claim(uint256 _pid) public {\n        require(surfPoolActive == true, \"surf pool not active\");\n        updatePool(_pid);\n        _claimRewardsFromPool(_pid, msg.sender);\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        PoolInfo memory pool = poolInfo[_pid];\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12);\n    }\n\n    // Claim all earned SURF and UNI from all pools. Claiming won\u0027t work until surfPoolActive == true\n    function claimAll() public {\n        require(surfPoolActive == true, \"surf pool not active\");\n\n        uint256 totalPendingSurfAmount = 0;\n        uint256 totalPendingUniAmount = 0;\n        \n        uint256 length = poolInfo.length;\n        for (uint256 pid = 0; pid \u003c length; ++pid) {\n            UserInfo storage user = userInfo[pid][msg.sender];\n\n            if (user.staked \u003e 0) {\n                updatePool(pid);\n\n                PoolInfo storage pool = poolInfo[pid];\n                uint256 accSurfPerShare = pool.accSurfPerShare;\n                uint256 accUniPerShare = pool.accUniPerShare;\n\n                uint256 pendingPoolSurfRewards = user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n                user.claimed += pendingPoolSurfRewards;\n                totalPendingSurfAmount = totalPendingSurfAmount.add(pendingPoolSurfRewards);\n                user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n\n                uint256 pendingPoolUniRewards = user.staked.mul(accUniPerShare).div(1e12).sub(user.uniRewardDebt);\n                user.uniClaimed += pendingPoolUniRewards;\n                totalPendingUniAmount = totalPendingUniAmount.add(pendingPoolUniRewards);\n                user.uniRewardDebt = user.staked.mul(accUniPerShare).div(1e12);\n            }\n        }\n\n        require(totalPendingSurfAmount \u003e 0 || totalPendingUniAmount \u003e 0, \"nothing to claim\");\n\n        uint256 uniBalance = uniToken.balanceOf(address(this));\n        if (totalPendingUniAmount \u003e uniBalance) totalPendingUniAmount = uniBalance;\n        if (totalPendingUniAmount \u003e 0) uniToken.transfer(msg.sender, totalPendingUniAmount);\n\n        if (totalPendingSurfAmount \u003e 0) _safeSurfTransfer(msg.sender, totalPendingSurfAmount);\n\n        emit ClaimAll(msg.sender, totalPendingSurfAmount, totalPendingUniAmount);\n    }\n\n    // Withdraw LP tokens and earned SURF from Tito. Withdrawing won\u0027t work until surfPoolActive == true\n    function withdraw(uint256 _pid, uint256 _amount) public {\n        require(surfPoolActive == true, \"surf pool not active\");\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        require(_amount \u003e 0 \u0026\u0026 user.staked \u003e= _amount, \"withdraw: not good\");\n        \n        updatePool(_pid);\n\n        // Claim any pending SURF and UNI\n        _claimRewardsFromPool(_pid, msg.sender);\n\n        PoolInfo memory pool = poolInfo[_pid];\n\n        // If a UNI staking rewards contract is in use, withdraw from it\n        if (pool.uniStakeContract != address(0)) {\n            IStakingRewards(pool.uniStakeContract).withdraw(_amount);\n        }\n\n        user.staked = user.staked.sub(_amount);\n        user.rewardDebt = user.staked.mul(pool.accSurfPerShare).div(1e12);\n        user.uniRewardDebt = user.staked.mul(pool.accUniPerShare).div(1e12);\n\n        pool.lpToken.safeTransfer(address(msg.sender), _amount);\n        emit Withdraw(msg.sender, _pid, _amount);\n    }\n\n    // Convenience function to allow users to migrate all of their staked SURF-ETH LP tokens from Tito to the Whirlpool staking contract after the max supply is hit. Migrating won\u0027t work until whirlpool.active() == true\n    function migrateSURFLPtoWhirlpool() public {\n        require(whirlpool.active() == true, \"whirlpool not active\");\n        UserInfo storage user = userInfo[0][msg.sender];\n        uint256 amountToMigrate = user.staked;\n        require(amountToMigrate \u003e 0, \"migrate: not good\");\n        \n        updatePool(0);\n\n        // Claim any pending SURF\n        _claimRewardsFromPool(0, msg.sender);\n\n        user.staked = 0;\n        user.rewardDebt = 0;\n\n        poolInfo[0].lpToken.safeApprove(address(whirlpool), 0);\n        poolInfo[0].lpToken.safeApprove(address(whirlpool), amountToMigrate);\n        whirlpool.stakeFor(msg.sender, amountToMigrate);\n        emit Withdraw(msg.sender, 0, amountToMigrate);\n    }\n\n    // Withdraw without caring about rewards. EMERGENCY ONLY.\n    function emergencyWithdraw(uint256 _pid) public {\n        UserInfo storage user = userInfo[_pid][msg.sender];\n        uint256 staked = user.staked;\n        require(staked \u003e 0, \"no tokens\");\n\n        PoolInfo memory pool = poolInfo[_pid];\n\n        // If a UNI staking rewards contract is in use, withdraw from it\n        if (pool.uniStakeContract != address(0)) {\n            IStakingRewards(pool.uniStakeContract).withdraw(staked);\n        }\n        \n        user.staked = 0;\n        user.rewardDebt = 0;\n        user.uniRewardDebt = 0;\n\n        pool.lpToken.safeTransfer(address(msg.sender), staked);\n        emit EmergencyWithdraw(msg.sender, _pid, staked);\n    }\n\n    // Internal function to safely transfer SURF in case there is a rounding error\n    function _safeSurfTransfer(address _to, uint256 _amount) internal {\n        uint256 surfBalance = surf.balanceOf(address(this));\n        if (_amount \u003e surfBalance) _amount = surfBalance;\n        surf.transfer(_to, _amount);\n    }\n\n    // Creates the SURF-ETH Uniswap pool and adds the initial liqudity that will be permanently locked. Can be called by anyone, but no sooner than 500 blocks after launch. \n    function activateSurfPool() public {\n        require(surfPoolActive == false, \"already active\");\n        require(block.number \u003e startBlock + SOFT_LAUNCH_DURATION.div(2), \"too soon\");\n        uint256 initialEthLiquidity = address(this).balance;\n        require(initialEthLiquidity \u003e 0, \"need ETH\");\n\n        massUpdatePools();\n\n        // The ETH raised from the staking fees collected before surfPoolActive == true is used to seed the ETH side of the SURF-ETH Uniswap pool.\n        // This means that the higher the staking volume during the first 500 blocks, the higher the initial price of SURF\n        if (donatedETH \u003e 0 \u0026\u0026 donatedETH \u003c initialEthLiquidity) initialEthLiquidity = initialEthLiquidity.sub(donatedETH);\n\n        // Mint 1,000,000 new SURF to seed the SURF liquidity in the SURF-ETH Uniswap pool\n        uint256 initialSurfLiquidity = 1000000 * 10**18;\n        surf.mint(address(this), initialSurfLiquidity);\n\n        // Add the liquidity to the SURF-ETH Uniswap pool\n        surf.approve(address(uniswapRouter), initialSurfLiquidity);\n        ( , , uint256 lpTokensReceived) = uniswapRouter.addLiquidityETH{value: initialEthLiquidity}(address(surf), initialSurfLiquidity, 0, 0, address(this), block.timestamp + 5 minutes);\n\n        // Activate the SURF-ETH pool\n        initialSurfPoolETH = initialEthLiquidity;\n        surfPoolActive = true;\n\n        // Permanently lock the LP tokens in the SURF contract\n        IERC20(surfPoolAddress).transfer(address(surf), lpTokensReceived);\n\n        // Buy SURF with all of the donatedETH from partner projects. This SURF will be sent to the Whirlpool staking contract and will start getting distributed to all stakers when the max supply is hit\n        uint256 donatedAmount = donatedETH;\n        uint256 ethBalance = address(this).balance;\n        if (donatedAmount \u003e ethBalance) donatedAmount = ethBalance;\n        if (donatedAmount \u003e 0) {\n            uint256 surfBought = _buySurf(donatedAmount);\n\n            // Send the SURF rewards to the Whirlpool staking contract\n            surfSentToWhirlpool += surfBought;\n            _safeSurfTransfer(address(whirlpool), surfBought);\n            donatedETH = 0;\n        }\n\n        emit SurfPoolActive(msg.sender, initialSurfLiquidity, initialEthLiquidity);\n    }\n\n    // For use by partner teams that are donating to the SURF community. The funds will be used to purchase SURF tokens which will be distributed to stakers once the max supply is hit\n    function donate(address _lpToken) public payable {\n        require(msg.value \u003e= minimumDonationAmount);\n        require(donaters[_lpToken] == address(0));\n\n        donatedETH = donatedETH.add(msg.value);\n        donaters[_lpToken] = msg.sender;\n        donations[_lpToken] = msg.value;\n    }\n\n    // For use by partner teams that donated to the SURF community. The funds can be removed if a beach wasn\u0027t created for the specified lp token (meaning the SURF team didn\u0027t hold up their end of the agreement)\n    function removeDonation(address _lpToken) public {\n        require(block.number \u003c startBlock); // Donations can only be removed if the beach hasn\u0027t been added by the startBlock\n        \n        address returnAddress = donaters[_lpToken];\n        require(msg.sender == returnAddress);\n        \n        uint256 donationAmount = donations[_lpToken];\n        require(donationAmount \u003e 0);\n        \n        uint256 ethBalance = address(this).balance;\n        require(donationAmount \u003c= ethBalance);\n\n        // Only refund the donation if the beach wasn\u0027t created\n        require(existingPools[_lpToken] != true);\n\n        donatedETH = donatedETH.sub(donationAmount);\n        donaters[_lpToken] = address(0);\n        donations[_lpToken] = 0;\n\n        msg.sender.transfer(donationAmount);\n    }\n\n    //////////////////////////\n    // Governance Functions //\n    //////////////////////////\n    // The following functions can only be called by the owner (the SURF token holder governance contract)\n\n    // Sets the address of the Whirlpool staking contract that bought SURF gets sent to for distribution to stakers once the max supply is hit\n    function setWhirlpoolContract(Whirlpool _whirlpool) public onlyOwner {\n        whirlpool = _whirlpool;\n    }\n\n    // Add a new LP Token pool\n    function addPool(address _token, address _lpToken, uint256 _apr, bool _requireDonation) public onlyOwner {\n        require(surf.maxSupplyHit() != true);\n        require(existingPools[_lpToken] != true, \"pool exists\");\n        require(_requireDonation != true || donations[_lpToken] \u003e= minimumDonationAmount, \"must donate\");\n\n        _addPool(_token, _lpToken);\n        if (_apr != DEFAULT_APR) poolInfo[poolInfo.length-1].apr = _apr;\n    }\n\n    // Update the given pool\u0027s APR\n    function setApr(uint256 _pid, uint256 _apr) public onlyOwner {\n        require(surf.maxSupplyHit() != true);\n        updatePool(_pid);\n        poolInfo[_pid].apr = _apr;\n    }\n\n    // Add a contract to the whitelist so that it can interact with Tito. This is needed for the Aegis pool contract to be able to stake on behalf of everyone in the pool.\n    // We want limited interaction from contracts due to the growing \"flash loan\" trend that can be used to dramatically manipulate a token\u0027s price in a single block.\n    function addToWhitelist(address _contractAddress) public onlyOwner {\n        contractWhitelist[_contractAddress] = true;\n    }\n\n    // Remove a contract from the whitelist\n    function removeFromWhitelist(address _contractAddress) public onlyOwner {\n        contractWhitelist[_contractAddress] = false;\n    }\n\n}"},"UniStakingInterfaces.sol":{"content":"pragma solidity ^0.6.12;\n\ninterface StakingRewardsFactory {\n    function stakingRewardsInfoByStakingToken(address) external view returns (address, uint256);\n}\n\ninterface IStakingRewards {\n    // Views\n    function lastTimeRewardApplicable() external view returns (uint256);\n\n    function rewardPerToken() external view returns (uint256);\n\n    function earned(address account) external view returns (uint256);\n\n    function getRewardForDuration() external view returns (uint256);\n\n    function totalSupply() external view returns (uint256);\n\n    function balanceOf(address account) external view returns (uint256);\n\n    // Mutative\n\n    function stake(uint256 amount) external;\n\n    function withdraw(uint256 amount) external;\n\n    function getReward() external;\n\n    function exit() external;\n}"},"Whirlpool.sol":{"content":"\n/*\n   _____ __  ______  ______     ___________   _____    _   ______________\n  / ___// / / / __ \\/ ____/    / ____/  _/ | / /   |  / | / / ____/ ____/\n  \\__ \\/ / / / /_/ / /_       / /_   / //  |/ / /| | /  |/ / /   / __/   \n ___/ / /_/ / _, _/ __/  _   / __/ _/ // /|  / ___ |/ /|  / /___/ /___   \n/____/\\____/_/ |_/_/    (_) /_/   /___/_/ |_/_/  |_/_/ |_/\\____/_____/  \n\nWebsite: https://surf.finance\nCreated by Proof and sol_dev, with help from Zoma and Mr Fahrenheit\nAudited by Aegis DAO and Sherlock Security\n\n*/\n\npragma solidity ^0.6.12;\n\nimport \u0027./Ownable.sol\u0027;\nimport \u0027./SafeMath.sol\u0027;\nimport \u0027./SafeERC20.sol\u0027;\nimport \u0027./IERC20.sol\u0027;\nimport \u0027./IUniswapV2Router02.sol\u0027;\nimport \u0027./SURF.sol\u0027;\nimport \u0027./Tito.sol\u0027;\n\n// The Whirlpool staking contract becomes active after the max supply it hit, and is where SURF-ETH LP token stakers will continue to receive dividends from other projects in the SURF ecosystem\ncontract Whirlpool is Ownable {\n    using SafeMath for uint256;\n    using SafeERC20 for IERC20;\n\n    // Info of each user\n    struct UserInfo {\n        uint256 staked; // How many SURF-ETH LP tokens the user has staked\n        uint256 rewardDebt; // Reward debt. Works the same as in the Tito contract\n        uint256 claimed; // Tracks the amount of SURF claimed by the user\n    }\n\n    // The SURF TOKEN!\n    SURF public surf;\n    // The Tito contract\n    Tito public tito;\n    // The SURF-ETH Uniswap LP token\n    IERC20 public surfPool;\n    // The Uniswap v2 Router\n    IUniswapV2Router02 public uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);\n    // WETH\n    IERC20 public weth;\n\n    // Info of each user that stakes SURF-ETH LP tokens\n    mapping (address =\u003e UserInfo) public userInfo;\n    // The amount of SURF sent to this contract before it became active\n    uint256 public initialSurfReward = 0;\n    // 1% of the initialSurfReward will be rewarded to stakers per day for 100 days\n    uint256 public initialSurfRewardPerDay;\n    // How often the initial 1% payouts can be processed\n    uint256 public constant INITIAL_PAYOUT_INTERVAL = 24 hours;\n    // The unstaking fee that is used to increase locked liquidity and reward Whirlpool stakers (1 = 0.1%). Defaults to 10%\n    uint256 public unstakingFee = 100;\n    // The amount of SURF-ETH LP tokens kept by the unstaking fee that will be converted to SURF and distributed to stakers (1 = 0.1%). Defaults to 50%\n    uint256 public unstakingFeeConvertToSurfAmount = 500;\n    // When the first 1% payout can be processed (timestamp). It will be 24 hours after the Whirlpool contract is activated\n    uint256 public startTime;\n    // When the last 1% payout was processed (timestamp)\n    uint256 public lastPayout;\n    // The total amount of pending SURF available for stakers to claim\n    uint256 public totalPendingSurf;\n    // Accumulated SURFs per share, times 1e12.\n    uint256 public accSurfPerShare;\n    // The total amount of SURF-ETH LP tokens staked in the contract\n    uint256 public totalStaked;\n    // Becomes true once the \u0027activate\u0027 function called by the Tito contract when the max SURF supply is hit\n    bool public active = false;\n\n    event Stake(address indexed user, uint256 amount);\n    event Claim(address indexed user, uint256 surfAmount);\n    event Withdraw(address indexed user, uint256 amount);\n    event SurfRewardAdded(address indexed user, uint256 surfReward);\n    event EthRewardAdded(address indexed user, uint256 ethReward);\n\n    constructor(SURF _surf, Tito _tito) public {\n        tito = _tito;\n        surf = _surf;\n        surfPool = IERC20(tito.surfPoolAddress());\n        weth = IERC20(uniswapRouter.WETH());\n    }\n\n    receive() external payable {\n        emit EthRewardAdded(msg.sender, msg.value);\n    }\n\n    function activate() public {\n        require(active != true, \"already active\");\n        require(surf.maxSupplyHit() == true, \"too soon\");\n\n        active = true;\n\n        // Now that the Whirlpool staking contract is active, reward 1% of the initialSurfReward per day for 100 days\n        startTime = block.timestamp + INITIAL_PAYOUT_INTERVAL; // The first payout can be processed 24 hours after activation\n        lastPayout = startTime;\n        initialSurfRewardPerDay = initialSurfReward.div(100);\n    }\n\n    // The _transfer function in the SURF contract calls this to let the Whirlpool contract know that it received the specified amount of SURF to be distributed to stakers \n    function addSurfReward(address _from, uint256 _amount) public {\n        require(msg.sender == address(surf), \"not surf contract\");\n        require(tito.surfPoolActive() == true, \"no surf pool\");\n        require(_amount \u003e 0, \"no surf\");\n\n        if (active != true || totalStaked == 0) {\n            initialSurfReward = initialSurfReward.add(_amount);\n        } else {\n            totalPendingSurf = totalPendingSurf.add(_amount);\n            accSurfPerShare = accSurfPerShare.add(_amount.mul(1e12).div(totalStaked));\n        }\n\n        emit SurfRewardAdded(_from, _amount);\n    }\n\n    // Allows external sources to add ETH to the contract which is used to buy and then distribute SURF to stakers\n    function addEthReward() public payable {\n        require(tito.surfPoolActive() == true, \"no surf pool\");\n\n        // We will purchase SURF with all of the ETH in the contract in case some was sent directly to the contract instead of using addEthReward\n        uint256 ethBalance = address(this).balance;\n        require(ethBalance \u003e 0, \"no eth\");\n\n        // Use the ETH to buyback SURF which will be distributed to stakers\n        _buySurf(ethBalance);\n\n        // The _transfer function in the SURF contract calls the Whirlpool contract\u0027s updateSurfReward function so we don\u0027t need to update the balances after buying the SURF\n        emit EthRewardAdded(msg.sender, msg.value);\n    }\n\n    // Internal function to buy back SURF with the amount of ETH specified\n    function _buySurf(uint256 _amount) internal {\n        uint256 deadline = block.timestamp + 5 minutes;\n        address[] memory surfPath = new address[](2);\n        surfPath[0] = address(weth);\n        surfPath[1] = address(surf);\n        uniswapRouter.swapExactETHForTokens{value: _amount}(0, surfPath, address(this), deadline);\n    }\n\n    // Handles paying out the initialSurfReward over 100 days\n    function _processInitialPayouts() internal {\n        if (active != true || block.timestamp \u003c startTime || initialSurfReward == 0 || totalStaked == 0) return;\n\n        // How many days since last payout?\n        uint256 daysSinceLastPayout = (block.timestamp - lastPayout) / INITIAL_PAYOUT_INTERVAL;\n\n        // If less than 1, don\u0027t do anything\n        if (daysSinceLastPayout == 0) return;\n\n        // Work out how many payouts have been missed\n        uint256 nextPayoutNumber = (block.timestamp - startTime) / INITIAL_PAYOUT_INTERVAL;\n        uint256 previousPayoutNumber = nextPayoutNumber - daysSinceLastPayout;\n\n        // Calculate how much additional reward we have to hand out\n        uint256 surfReward = rewardAtPayout(nextPayoutNumber) - rewardAtPayout(previousPayoutNumber);\n        if (surfReward \u003e initialSurfReward) surfReward = initialSurfReward;\n        initialSurfReward = initialSurfReward.sub(surfReward);\n\n        // Payout the surfReward to the stakers\n        totalPendingSurf = totalPendingSurf.add(surfReward);\n        accSurfPerShare = accSurfPerShare.add(surfReward.mul(1e12).div(totalStaked));\n\n        // Update lastPayout time\n        lastPayout += (daysSinceLastPayout * INITIAL_PAYOUT_INTERVAL);\n    }\n\n    // Handles claiming the user\u0027s pending SURF rewards\n    function _claimReward(address _user) internal {\n        UserInfo storage user = userInfo[_user];\n        if (user.staked \u003e 0) {\n            uint256 pendingSurfReward = user.staked.mul(accSurfPerShare).div(1e12).sub(user.rewardDebt);\n            if (pendingSurfReward \u003e 0) {\n                totalPendingSurf = totalPendingSurf.sub(pendingSurfReward);\n                user.claimed += pendingSurfReward;\n                _safeSurfTransfer(_user, pendingSurfReward);\n                emit Claim(_user, pendingSurfReward);\n            }\n        }\n    }\n\n    // Stake SURF-ETH LP tokens to get rewarded with more SURF\n    function stake(uint256 _amount) public {\n        stakeFor(msg.sender, _amount);\n    }\n\n    // Stake SURF-ETH LP tokens on behalf of another address\n    function stakeFor(address _user, uint256 _amount) public {\n        require(active == true, \"not active\");\n        require(_amount \u003e 0, \"stake something\");\n\n        _processInitialPayouts();\n\n        // Claim any pending SURF\n        _claimReward(_user);\n\n        surfPool.safeTransferFrom(address(msg.sender), address(this), _amount);\n\n        UserInfo storage user = userInfo[_user];\n        totalStaked = totalStaked.add(_amount);\n        user.staked = user.staked.add(_amount);\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n        emit Stake(_user, _amount);\n    }\n\n    // Claim earned SURF. Claiming won\u0027t work until active == true\n    function claim() public {\n        require(active == true, \"not active\");\n        UserInfo storage user = userInfo[msg.sender];\n        require(user.staked \u003e 0, \"no stake\");\n        \n        _processInitialPayouts();\n\n        // Claim any pending SURF\n        _claimReward(msg.sender);\n\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n    }\n\n    // Unstake and withdraw SURF-ETH LP tokens and any pending SURF rewards. There is a 10% unstaking fee, meaning the user will only receive 90% of their LP tokens back.\n    // For the LP tokens kept by the unstaking fee, 50% will get locked forever in the SURF contract, and 50% will get converted to SURF and distributed to stakers.\n    function withdraw(uint256 _amount) public {\n        require(active == true, \"not active\");\n        UserInfo storage user = userInfo[msg.sender];\n        require(_amount \u003e 0 \u0026\u0026 user.staked \u003e= _amount, \"withdraw: not good\");\n        \n        _processInitialPayouts();\n\n        uint256 unstakingFeeAmount = _amount.mul(unstakingFee).div(1000);\n        uint256 remainingUserAmount = _amount.sub(unstakingFeeAmount);\n\n        // Half of the LP tokens kept by the unstaking fee will be locked forever in the SURF contract, the other half will be converted to SURF and distributed to stakers\n        uint256 lpTokensToConvertToSurf = unstakingFeeAmount.mul(unstakingFeeConvertToSurfAmount).div(1000);\n        uint256 lpTokensToLock = unstakingFeeAmount.sub(lpTokensToConvertToSurf);\n\n        // Remove the liquidity from the Uniswap SURF-ETH pool and buy SURF with the ETH received\n        // The _transfer function in the SURF.sol contract automatically calls whirlpool.addSurfReward() so we don\u0027t have to in this function\n        if (lpTokensToConvertToSurf \u003e 0) {\n            surfPool.safeApprove(address(uniswapRouter), lpTokensToConvertToSurf);\n            uniswapRouter.removeLiquidityETHSupportingFeeOnTransferTokens(address(surf), lpTokensToConvertToSurf, 0, 0, address(this), block.timestamp + 5 minutes);\n            addEthReward();\n        }\n\n        // Permanently lock the LP tokens in the SURF contract\n        if (lpTokensToLock \u003e 0) surfPool.transfer(address(surf), lpTokensToLock);\n\n        // Claim any pending SURF\n        _claimReward(msg.sender);\n\n        totalStaked = totalStaked.sub(_amount);\n        user.staked = user.staked.sub(_amount);\n        surfPool.safeTransfer(address(msg.sender), remainingUserAmount);\n        user.rewardDebt = user.staked.mul(accSurfPerShare).div(1e12);\n        emit Withdraw(msg.sender, remainingUserAmount);\n    }\n\n    // Internal function to safely transfer SURF in case there is a rounding error\n    function _safeSurfTransfer(address _to, uint256 _amount) internal {\n        uint256 surfBal = surf.balanceOf(address(this));\n        if (_amount \u003e surfBal) {\n            surf.transfer(_to, surfBal);\n        } else {\n            surf.transfer(_to, _amount);\n        }\n    }\n\n    // Sets the unstaking fee. Can\u0027t be higher than 50%. _convertToSurfAmount is the % of the LP tokens from the unstaking fee that will be converted to SURF and distributed to stakers.\n    // unstakingFee - unstakingFeeConvertToSurfAmount = The % of the LP tokens from the unstaking fee that will be permanently locked in the SURF contract\n    function setUnstakingFee(uint256 _unstakingFee, uint256 _convertToSurfAmount) public onlyOwner {\n        require(_unstakingFee \u003c= 500, \"over 50%\");\n        require(_convertToSurfAmount \u003c= 1000, \"bad amount\");\n        unstakingFee = _unstakingFee;\n        unstakingFeeConvertToSurfAmount = _convertToSurfAmount;\n    }\n\n    // Function to recover ERC20 tokens accidentally sent to the contract.\n    // SURF and SURF-ETH LP tokens (the only 2 ERC2O\u0027s that should be in this contract) can\u0027t be withdrawn this way.\n    function recoverERC20(address _tokenAddress) public onlyOwner {\n        require(_tokenAddress != address(surf) \u0026\u0026 _tokenAddress != address(surfPool));\n        IERC20 token = IERC20(_tokenAddress);\n        uint256 tokenBalance = token.balanceOf(address(this));\n        token.transfer(msg.sender, tokenBalance);\n    }\n\n    function payoutNumber() public view returns (uint256) {\n        if (block.timestamp \u003c startTime) return 0;\n\n        uint256 payout = (block.timestamp - startTime).div(INITIAL_PAYOUT_INTERVAL);\n        if (payout \u003e 100) return 100;\n        else return payout;\n    }\n\n    function timeUntilNextPayout() public view returns (uint256) {\n        if (initialSurfReward == 0) return 0;\n        else {\n            uint256 payout = payoutNumber();\n            uint256 nextPayout = startTime.add((payout + 1).mul(INITIAL_PAYOUT_INTERVAL));\n            return nextPayout - block.timestamp;\n        }\n    }\n\n    function rewardAtPayout(uint256 _payoutNumber) public view returns (uint256) {\n        if (_payoutNumber == 0) return 0;\n        return initialSurfRewardPerDay * _payoutNumber;\n    }\n\n    function getAllInfoFor(address _user) external view returns (bool isActive, uint256[12] memory info) {\n        isActive = active;\n        info[0] = surf.balanceOf(address(this));\n        info[1] = initialSurfReward;\n        info[2] = totalPendingSurf;\n        info[3] = startTime;\n        info[4] = lastPayout;\n        info[5] = totalStaked;\n        info[6] = surf.balanceOf(_user);\n        if (tito.surfPoolActive()) {\n            info[7] = surfPool.balanceOf(_user);\n            info[8] = surfPool.allowance(_user, address(this));\n        }\n        info[9] = userInfo[_user].staked;\n        info[10] = userInfo[_user].staked.mul(accSurfPerShare).div(1e12).sub(userInfo[_user].rewardDebt);\n        info[11] = userInfo[_user].claimed;\n    }\n\n}"}}