// ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
// ░░░░░░░░░░░░░▒▓██████████████████████████▓░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
// ░░░░░░░░░░░░▓█▓░░░░░░░░░░░░░░░░░░░░░░░░░░▓█▒░░░░░░▓▓░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
// ░░░░░░░░░░░▒██░░▒▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓░░▒██▓░░░░▒█████▓░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░▓███▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
// ░░░░░▒░░░░░▓█▒░░███████▓▒▒▒▒▒▒▒▓███████░░▒███▓░▒▓██████░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░▒▓▓▓▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
// ░░░░░▒▒▒▒▒▓█▓░░▒███████░░░░░░░░▒███████░░▒████▓▓▓███████▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓██▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒░░░░░░░░░
// ░░░░▒▒▒▒▒▒██░░░███████▒░░░░░░░░▒███████░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░▒▓█▓░░░░░░░░
// ░░░░▒▒▒▒▒▓█▓░░▓███████░░░░░░░░░███████▒░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░▒░▒▒░▒▒░▒▒▒▒▒▒▒▒▒▒▒▒▒░▒░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░░▓█▓░░░░░░░
// ░░░░░▒▒▒░██░░░███████▒░░░░░░░░▒███████░█▓░█████▓▓▓▓▓▓▓▓▓▓▓▓░▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▒▒▓▓▓▒░▒▓░░▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓████████░▒▒▒▓███▓▒▒███████▓▓▓███████░░░████░░░░░░
// ░░░░░░░░▒█▓░░▓███████░░░░░░░░░███████▒▒███████░░░░░░░░░░░░░░▓▓▓▓▓▓▓░░░░░░░░░▒▓▓▓▓▒▓▒░░░░░░░░░░░░░░░░░███████▒░▓▒▓███▓░░░██████▓░░▒██████▓░░▓████▒░░░░░
// ░░░░░░░░██░░░███████░░░░░░░░░▓██████▓░███████▒░░▓███████▒░░▒▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒▓▓▓▓▒░████████████████████████░▒██████▒░░▓██████░░░███████░░░█████░░░░░░
// ░░░░█▒▒▓█▓░░▓███████░░░░░░░░▓█▓▓▒▓█▓░▒███████░░▒████████░░░▓▓▓▓▓▓▓░░░░░░░░░░░░░░░░░▒███████░░░░░░░░░███▓▓▓█▒░██████▓░░░██████▓░░▒██████▓░░▓████▒░░░░░░
// ░░▒▓██▓██░░░███████▓▓▓▓▓▓▓▓▓██▓░▒█▓░░███████▒░░▓████▓██▒░░▒▓▓▓▓▓▓▓▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░████████▓▓▓▓▓▓▓▓▓███▒░▓▓░▓██████▒░░▓██████░░░███▓░▒█░░▒█████░░░░░░░
// ░░░░▒░▒█▓░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░░▒▒▒▒▒▒▒░░▒████▓░██░░░▒▒░▒▒▒▒▒▒▒▒▒▒░▒▒░▒▒░▒▒░░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░▒▒▒▒▒▒▒░░░▒▒▒▒▒▒▒░░░▒▒▒▒▒▒░░░▓████▓▒▒▒▒░░░
// ░░░░░░██░░░▓▓▓▓▓▓▓▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░░░░░░░░░░░░▒█████░░▒█▓▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░▒▒░░░░░▒▒░░░░░▓▓▓▓▓▓▒░░▒█████▒▒▒▒▒░░░
// ░░░░░▒█▓░░▒██████▓▒▒▒▒▒▒▓███████░░▒███████████████▒░░░░▓█████████████████████████████▓░░░░░░░░░░░░████████████░░░▓▓▒░░░░░░▒▓▒░▓▒▓████░░░▒▓███▓▒▒▒▒▒▒░░
// ░░░░░██░░░███████▒░░░░░░███████▒░░▓███████████████▓▓▓▓▓██████████████████████████████░░░▓▓▓▓▓▒▓░░░████████████▓░░░▓░░▓▓▒░░░▒░░█▓████▒░▒░░░░▓█▓▒▒░░░░░░
// ░░░░▒█▓░░▒██████▓░░░░░░▒███████░░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░░░▓▓▓▓░▒▒░░░▒▒▒▒▒▒▒▒▒▒▒▒░░░▓█▒░░░░░▒▒░░▓█████▒▓▒███▒░░▓██░░░░░░░
// ░░░░██░░░███████▓▒▒▒▒▒▒███████▓▒░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░░░░▓▓▓▓▓▓▒░░░░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░░███▓▓▓▒█▓▒██▓░░▓███░░░░░░
// ░░░▒█▓░░▓███████▓▓▓▓▓▓▓▓▓███████░░███████▓▓▓▓▓▓▓▓▓███████▓░░▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓████▒▓█░▓▓▓▓▓▓▓▓▒▓▓▓▓░░▒▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▓▓▓▓▒░░░░▓▓▓█▓▓▒▒▓▓░▒░░▒████▓░░░░░
// ░░░██░░░███████░░░░░░░░░▓██████▓░▓███████░░░░░░░░░███▒░▒█░░░░░░░░░░░░░░░░░░█████▓█▒░▓▓▓▓▓▓▓▒▓▓▓▓░░░░░░░░░░░░▒▓▓▓▓▓▓▓▓▒░░░░░░▓██▓▒▓░░░░░░░▒▓█████▒░░░░░
// ░░▓█▓░░▓██████▓░░░░░░░░▒███████░░████████████████████▓██▓░▓███████████████████████░░░░▓▓▓▓▓▓░░░░░░░░░░░░░▒▓▓▓▓▓▓▓▓▒░░░░░░▒▒▒▓▓▓▓▓▒░░░░░░░▓██████░░░░░░
// ░░██░░░▓░▒▓███░░░░░░░░░▓██████▓░▓███████░░░░░░░░░░░░░░░░░▒███████░░░░░░░░░███████▒░░░░█████▓░░░░░░░░░░▒▓▓▓▓▓▓▓▓▒░░░░░░░░░▒▒▒▒▒▒▒▒░░░░░▒▒░░████▓▒░░░░░░
// ░▓█▒░░▓█▒█████▒▒▒▒▒▒▒▒▓███████░░███████▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓░░███████▓▒▒▒▒▒▒▒▒▓███████░░░████████▓▓▓░░░░▒▓▓▓▓▓▓▓▓▓▓▒▒▒▒▒▒▒▒▒▒░░▓█████▓░░░▒▒▒░░▒████▒██▓░░░░
// ░██░░░▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒░▒▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒░░▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒░░░▓▓▓▓▓▓▓▓▓▓▓░░░▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒░░▓▓▓▓▓▓░░░░░░░▒▓█████▓█▓▓░░░░
// ░▒█▓▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░▒▓▓█████████░░░░░░░░
// ░░▒█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████▓░░░░░░░░░
// ░░░▒█████████████████████████████████████████████████████▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒▒▒▓▓▓▓▓▓▓▓▓▓▓▓█████████████████████████████████████████████████▓▒░░░░░░░░░░░
// ░░░░░▒▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒░░░░░░░░░░░░░░░░░
// ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░

// SPDX-License-Identifier: MIT
pragma solidity 0.8.7;  
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}
interface IOperatorFilterRegistry {
    function isOperatorAllowed(address registrant, address operator) external view returns (bool);
    function register(address registrant) external;
    function registerAndSubscribe(address registrant, address subscription) external;
    function registerAndCopyEntries(address registrant, address registrantToCopy) external;
    function unregister(address addr) external;
    function updateOperator(address registrant, address operator, bool filtered) external;
    function updateOperators(address registrant, address[] calldata operators, bool filtered) external;
    function updateCodeHash(address registrant, bytes32 codehash, bool filtered) external;
    function updateCodeHashes(address registrant, bytes32[] calldata codeHashes, bool filtered) external;
    function subscribe(address registrant, address registrantToSubscribe) external;
    function unsubscribe(address registrant, bool copyExistingEntries) external;
    function subscriptionOf(address addr) external returns (address registrant);
    function subscribers(address registrant) external returns (address[] memory);
    function subscriberAt(address registrant, uint256 index) external returns (address);
    function copyEntriesOf(address registrant, address registrantToCopy) external;
    function isOperatorFiltered(address registrant, address operator) external returns (bool);
    function isCodeHashOfFiltered(address registrant, address operatorWithCode) external returns (bool);
    function isCodeHashFiltered(address registrant, bytes32 codeHash) external returns (bool);
    function filteredOperators(address addr) external returns (address[] memory);
    function filteredCodeHashes(address addr) external returns (bytes32[] memory);
    function filteredOperatorAt(address registrant, uint256 index) external returns (address);
    function filteredCodeHashAt(address registrant, uint256 index) external returns (bytes32);
    function isRegistered(address addr) external returns (bool);
    function codeHashOf(address addr) external returns (bytes32);
}
abstract contract OperatorFilterer {
    error OperatorNotAllowed(address operator);

    IOperatorFilterRegistry public constant OPERATOR_FILTER_REGISTRY =
        IOperatorFilterRegistry(0x000000000000AAeB6D7670E522A718067333cd4E);

    constructor(address subscriptionOrRegistrantToCopy, bool subscribe) {
        // If an inheriting token contract is deployed to a network without the registry deployed, the modifier
        // will not revert, but the contract will need to be registered with the registry once it is deployed in
        // order for the modifier to filter addresses.
        if (address(OPERATOR_FILTER_REGISTRY).code.length > 0) {
            if (subscribe) {
                OPERATOR_FILTER_REGISTRY.registerAndSubscribe(address(this), subscriptionOrRegistrantToCopy);
            } else {
                if (subscriptionOrRegistrantToCopy != address(0)) {
                    OPERATOR_FILTER_REGISTRY.registerAndCopyEntries(address(this), subscriptionOrRegistrantToCopy);
                } else {
                    OPERATOR_FILTER_REGISTRY.register(address(this));
                }
            }
        }
    }

    modifier onlyAllowedOperator(address from) virtual {
        // Allow spending tokens from addresses with balance
        // Note that this still allows listings and marketplaces with escrow to transfer tokens if transferred
        // from an EOA.
        if (from != msg.sender) {
            _checkFilterOperator(msg.sender);
        }
        _;
    }

    modifier onlyAllowedOperatorApproval(address operator) virtual {
        _checkFilterOperator(operator);
        _;
    }
    
    function _checkFilterOperator(address operator) internal view virtual {
        // Check registry code length to facilitate testing in environments without a deployed registry.
        if (address(OPERATOR_FILTER_REGISTRY).code.length > 0) {
            if (!OPERATOR_FILTER_REGISTRY.isOperatorAllowed(address(this), operator)) {
                revert OperatorNotAllowed(operator);
            }
        }
    }
}
abstract contract DefaultOperatorFilterer is OperatorFilterer {
    address constant DEFAULT_SUBSCRIPTION = address(0x3cc6CddA760b79bAfa08dF41ECFA224f810dCeB6);

    constructor() OperatorFilterer(DEFAULT_SUBSCRIPTION, true) {}
} 
library MerkleProof {
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }
   function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];
            if (computedHash <= proofElement) {
                computedHash = _efficientHash(computedHash, proofElement);
            } else {
                computedHash = _efficientHash(proofElement, computedHash);
            }
        }
        return computedHash;
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}
abstract contract ReentrancyGuard { 
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }
    modifier nonReentrant() {
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
   _status = _ENTERED;

        _;
        _status = _NOT_ENTERED;
    }
}

library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
 
    function toString(uint256 value) internal pure returns (string memory) { 
        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }
 
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }
 
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}
 
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
 
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
 
    constructor() {
        _transferOwnership(_msgSender());
    }
 
    function owner() public view virtual returns (address) {
        return _owner;
    } 
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
 
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }
 
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }
 
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
 
library Address { 
    function isContract(address account) internal view returns (bool) { 
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    } 
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
 
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    } 
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
 
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
 
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    } 
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
 
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
 
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
 
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
 
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else { 
            if (returndata.length > 0) { 

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
 
interface IERC721Receiver { 
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}
 
interface IERC165 { 
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
 
abstract contract ERC165 is IERC165 { 
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
} 
interface IERC721 is IERC165 { 
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); 
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); 
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved); 
    function balanceOf(address owner) external view returns (uint256 balance); 
    function ownerOf(uint256 tokenId) external view returns (address owner); 
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external; 
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external; 
    function approve(address to, uint256 tokenId) external;
 
    function getApproved(uint256 tokenId) external view returns (address operator); 
    function setApprovalForAll(address operator, bool _approved) external; 
    function isApprovedForAll(address owner, address operator) external view returns (bool); 
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;
}
interface IERC721Metadata is IERC721 { 
    function name() external view returns (string memory); 
    function symbol() external view returns (string memory); 
    function tokenURI(uint256 tokenId) external view returns (string memory);
} 
interface IERC721Enumerable is IERC721 { 
    function totalSupply() external view returns (uint256); 
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId); 
    function tokenByIndex(uint256 index) external view returns (uint256);
} 
error ApprovalCallerNotOwnerNorApproved();
error ApprovalQueryForNonexistentToken();
error ApproveToCaller();
error ApprovalToCurrentOwner();
error BalanceQueryForZeroAddress();
error MintToZeroAddress();
error MintZeroQuantity();
error OwnerQueryForNonexistentToken();
error TransferCallerNotOwnerNorApproved();
error TransferFromIncorrectOwner();
error TransferToNonERC721ReceiverImplementer();
error TransferToZeroAddress();
error URIQueryForNonexistentToken();

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension. Built to optimize for lower gas during batch mints.
 *
 * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
 *
 * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 *
 * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable, Ownable {
    using Address for address;
    using Strings for uint256;

    // Compiler will pack this into a single 256bit word.
    struct TokenOwnership {
        // The address of the owner.
        address addr;
        // Keeps track of the start time of ownership with minimal overhead for tokenomics.
        uint64 startTimestamp;
        // Whether the token has been burned.
        bool burned;
    }

    // Compiler will pack this into a single 256bit word.
    struct AddressData {
        // Realistically, 2**64-1 is more than enough.
        uint64 balance;
        // Keeps track of mint count with minimal overhead for tokenomics.
        uint64 numberMinted;
        // Keeps track of burn count with minimal overhead for tokenomics.
        uint64 numberBurned;
        // For miscellaneous variable(s) pertaining to the address
        // (e.g. number of whitelist mint slots used).
        // If there are multiple variables, please pack them into a uint64.
        uint64 aux;
    }

    // The tokenId of the next token to be minted.
    uint256 internal _currentIndex;

    // The number of tokens burned.
    uint256 internal _burnCounter;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to ownership details
    // An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.
    mapping(uint256 => TokenOwnership) internal _ownerships;

    // Mapping owner address to address data
    mapping(address => AddressData) private _addressData;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _currentIndex = _startTokenId();
    }

    /**
     * To change the starting tokenId, please override this function.
     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    /**
     * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
     */
    function totalSupply() public view override returns (uint256) {
        return _currentIndex;
    } 
    function tokenByIndex(uint256 index) public view override returns (uint256) {
        require(index < totalSupply(), "ERC721A: global index out of bounds");
        return index;
    } 
    function tokenOfOwnerByIndex(address owner, uint256 index)
        public
        view
        override
        returns (uint256)
    {
        require(index < balanceOf(owner), "ERC721A: owner index out of bounds");
        uint256 numMintedSoFar = totalSupply();
        uint256 tokenIdsIdx = 0;
        address currOwnershipAddr = address(0);
        for (uint256 i = 0; i < numMintedSoFar; i++) {
        TokenOwnership memory ownership = _ownerships[i];
        if (ownership.addr != address(0)) {
            currOwnershipAddr = ownership.addr;
        }
        if (currOwnershipAddr == owner) {
            if (tokenIdsIdx == index) {
            return i;
            }
            tokenIdsIdx++;
        }
        }
        revert("ERC721A: unable to get token of owner by index");
    } 

    /**
     * Returns the total amount of tokens minted in the contract.
     */
    function _totalMinted() internal view returns (uint256) {
        // Counter underflow is impossible as _currentIndex does not decrement,
        // and it is initialized to _startTokenId()
        unchecked {
            return _currentIndex - _startTokenId();
        }
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view override returns (uint256) {
        if (owner == address(0)) revert BalanceQueryForZeroAddress();
        return uint256(_addressData[owner].balance);
    }

    /**
     * Returns the number of tokens minted by `owner`.
     */
    function _numberMinted(address owner) internal view returns (uint256) {
        return uint256(_addressData[owner].numberMinted);
    }

    /**
     * Returns the number of tokens burned by or on behalf of `owner`.
     */
    function _numberBurned(address owner) internal view returns (uint256) {
        return uint256(_addressData[owner].numberBurned);
    }

    /**
     * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
     */
    function _getAux(address owner) internal view returns (uint64) {
        return _addressData[owner].aux;
    }

    /**
     * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
     * If there are multiple variables, please pack them into a uint64.
     */
    function _setAux(address owner, uint64 aux) internal {
        _addressData[owner].aux = aux;
    }

    /**
     * Gas spent here starts off proportional to the maximum mint batch size.
     * It gradually moves to O(1) as tokens get transferred around in the collection over time.
     */
    function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
        uint256 curr = tokenId;

        unchecked {
            if (_startTokenId() <= curr && curr < _currentIndex) {
                TokenOwnership memory ownership = _ownerships[curr];
                if (!ownership.burned) {
                    if (ownership.addr != address(0)) {
                        return ownership;
                    }
                    // Invariant:
                    // There will always be an ownership that has an address and is not burned
                    // before an ownership that does not have an address and is not burned.
                    // Hence, curr will not underflow.
                    while (true) {
                        curr--;
                        ownership = _ownerships[curr];
                        if (ownership.addr != address(0)) {
                            return ownership;
                        }
                    }
                }
            }
        }
        revert OwnerQueryForNonexistentToken();
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view override returns (address) {
        return _ownershipOf(tokenId).addr;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();

        string memory baseURI = _baseURI();
        return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overriden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721A.ownerOf(tokenId);
        if (to == owner) revert ApprovalToCurrentOwner();

        if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender())) {
            revert ApprovalCallerNotOwnerNorApproved();
        }

        _approve(to, tokenId, owner);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        if (operator == _msgSender()) revert ApproveToCaller();

        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        _transfer(from, to, tokenId);
        if (to.isContract() && !_checkContractOnERC721Received(from, to, tokenId, _data)) {
            revert TransferToNonERC721ReceiverImplementer();
        }
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     */
    function _exists(uint256 tokenId) internal view returns (bool) {
        return _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned;
    }

    function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, '');
    }

    /**
     * @dev Safely mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal {
        _mint(to, quantity, _data, true);
    }

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event.
     */
    function _mint(
        address to,
        uint256 quantity,
        bytes memory _data,
        bool safe
    ) internal {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are incredibly unrealistic.
        // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
        // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
        unchecked {
            _addressData[to].balance += uint64(quantity);
            _addressData[to].numberMinted += uint64(quantity);

            _ownerships[startTokenId].addr = to;
            _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);

            uint256 updatedIndex = startTokenId;
            uint256 end = updatedIndex + quantity;

            if (safe && to.isContract()) {
                do {
                    emit Transfer(address(0), to, updatedIndex);
                    if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
                        revert TransferToNonERC721ReceiverImplementer();
                    }
                } while (updatedIndex != end);
                // Reentrancy protection
                if (_currentIndex != startTokenId) revert();
            } else {
                do {
                    emit Transfer(address(0), to, updatedIndex++);
                } while (updatedIndex != end);
            }
            _currentIndex = updatedIndex;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) private {
        TokenOwnership memory prevOwnership = _ownershipOf(tokenId);

        if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();

        bool isApprovedOrOwner = (_msgSender() == from ||
            isApprovedForAll(from, _msgSender()) ||
            getApproved(tokenId) == _msgSender());

        if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId, from);

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
        unchecked {
            _addressData[from].balance -= 1;
            _addressData[to].balance += 1;

            TokenOwnership storage currSlot = _ownerships[tokenId];
            currSlot.addr = to;
            currSlot.startTimestamp = uint64(block.timestamp);

            // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
            uint256 nextTokenId = tokenId + 1;
            TokenOwnership storage nextSlot = _ownerships[nextTokenId];
            if (nextSlot.addr == address(0)) {
                // This will suffice for checking _exists(nextTokenId),
                // as a burned slot cannot contain the zero address.
                if (nextTokenId != _currentIndex) {
                    nextSlot.addr = from;
                    nextSlot.startTimestamp = prevOwnership.startTimestamp;
                }
            }
        }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

    /**
     * @dev This is equivalent to _burn(tokenId, false)
     */
    function _burn(uint256 tokenId) internal virtual {
        _burn(tokenId, false);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
        TokenOwnership memory prevOwnership = _ownershipOf(tokenId);

        address from = prevOwnership.addr;

        if (approvalCheck) {
            bool isApprovedOrOwner = (_msgSender() == from ||
                isApprovedForAll(from, _msgSender()) ||
                getApproved(tokenId) == _msgSender());

            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId, from);

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
        unchecked {
            AddressData storage addressData = _addressData[from];
            addressData.balance -= 1;
            addressData.numberBurned += 1;

            // Keep track of who burned the token, and the timestamp of burning.
            TokenOwnership storage currSlot = _ownerships[tokenId];
            currSlot.addr = from;
            currSlot.startTimestamp = uint64(block.timestamp);
            currSlot.burned = true;

            // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
            uint256 nextTokenId = tokenId + 1;
            TokenOwnership storage nextSlot = _ownerships[nextTokenId];
            if (nextSlot.addr == address(0)) {
                // This will suffice for checking _exists(nextTokenId),
                // as a burned slot cannot contain the zero address.
                if (nextTokenId != _currentIndex) {
                    nextSlot.addr = from;
                    nextSlot.startTimestamp = prevOwnership.startTimestamp;
                }
            }
        }

        emit Transfer(from, address(0), tokenId);
        _afterTokenTransfers(from, address(0), tokenId, 1);

        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
        unchecked {
            _burnCounter++;
        }
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(
        address to,
        uint256 tokenId,
        address owner
    ) private {
        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkContractOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
            return retval == IERC721Receiver(to).onERC721Received.selector;
        } catch (bytes memory reason) {
            if (reason.length == 0) {
                revert TransferToNonERC721ReceiverImplementer();
            } else {
                assembly {
                    revert(add(32, reason), mload(reason))
                }
            }
        }
    }

    /**
     * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
     * And also called before burning one token.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, `tokenId` will be burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**
     * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
     * minting.
     * And also called after one token has been burned.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
     * transferred to `to`.
     * - When `from` is zero, `tokenId` has been minted for `to`.
     * - When `to` is zero, `tokenId` has been burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}
}

interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract DreamBeatzGenesis is Ownable, ERC721A, ReentrancyGuard, DefaultOperatorFilterer  {
    using Strings for uint256;
    using SafeMath for uint256;
    uint256 public collectionSize = 5555;
    mapping(uint => uint) public level;

    string public uri = "https://bafkreic6isl34cafxhs64xy2owxujb5acnfmyt6uctdl7oaqwaj67qknqe.ipfs.nftstorage.link";
    function setURI(string memory u) public onlyOwner{
        uri = u;
    }
    
    address public beatzAddress;
    function setBeatzAddress(address a) public onlyOwner{
        beatzAddress = a;
    }
    
    address public beatz_vault;
    function setBeatzVault(address a) public onlyOwner{
        beatz_vault = a;
    }

    mapping(string => uint) public swapPrice;
    function set_swapPrice(string memory category, uint price_) public onlyOwner {
        swapPrice[category] = price_;
    }

    bool public reveal = false;
    function setReveal(bool set) public onlyOwner{
        reveal = set;
    }

    uint public status = 0; //0-stop 2-WL 3-PUBLIC
    function switch_status(uint Status) public onlyOwner {
        status = Status;
    }

    bool public status_trait_swap = false;
    function switch_status_trait_swap(bool Status) public onlyOwner {
        status_trait_swap = Status;
    }
    
    uint public mint_perAdd = 3;
    function set_mint_perAdd(uint new_) public onlyOwner {
        mint_perAdd = new_;
    }
    
    uint public price = 0.025 ether;
    function set_price(uint price_) public onlyOwner {
        price = price_;
    }

    bytes32 public merkleRoot_WL = 0x3e0e42f01476115c127a82967a00f112df4953c2cea3b4dc6b2421ac9251aa6a;
    function setMerkleRoot_WL(bytes32 m) public onlyOwner{
        merkleRoot_WL = m;
    }
    
    uint256 public reserve = 55;
    function setReserve(uint256 number) public onlyOwner {
        reserve = number;
    }

    ///////////////////////////////////////////////////////////////////////////

    constructor() ERC721A("DreamBeatz! Genesis", "DRMBTZ") {
        swapPrice["Background"] = 150 ether;
        swapPrice["Accessory 1"] = 200 ether;
        swapPrice["Accessory 2"] = 200 ether;
        swapPrice["Accessory 3"] = 200 ether;
        swapPrice["Accessory 4"] = 200 ether;
        swapPrice["Accessory 5"] = 200 ether;
        swapPrice["Body Trait"] = 200 ether;
        swapPrice["Clothes"] = 500 ether;
        swapPrice["Eyes"] = 300 ether;
        swapPrice["Hairstyle"] = 400 ether;
        swapPrice["Instrument Design"] = 500 ether;
        swapPrice["Mouth"] = 300 ether;
    }

    function giveaway(address recipient, uint256 quantity) public onlyOwner {
        require(totalSupply() + quantity <= collectionSize, "Giveaway exceeds current batch!!!");
        require(quantity <= reserve, "No more reserved remaining!!");

        _safeMint(recipient, quantity);
        reserve -= quantity;
    }

    function mint_list(uint256 quantity, bytes32[] calldata merkleproof) public payable {
        bytes32 leaf = keccak256(abi.encodePacked(msg.sender));

        if(status == 2)
        require(MerkleProof.verify( merkleproof, merkleRoot_WL, leaf),"Not whitelisted");

        require(numberMinted(msg.sender).add(quantity) <= mint_perAdd && quantity > 0, "Invalid mint quantity!!");
        require(msg.value >= quantity.mul(price), "Insufficient eth sent for mint!!");
        require(totalSupply().add(quantity) + reserve <= collectionSize, "Mint exceeds Collection size!!");        

        _safeMint(msg.sender, quantity);
    }

    function mint(uint256 quantity) public payable {
        require(status == 3, "Minting not active!!");
        require(numberMinted(msg.sender).add(quantity) <= mint_perAdd && quantity > 0, "Invalid mint quantity!!");
        require(msg.value >= quantity.mul(price), "Insufficient eth sent for mint!!");
        require(totalSupply().add(quantity) + reserve <= collectionSize, "Mint exceeds Collection size!!");        

        _safeMint(msg.sender, quantity);
    }

    function swapTrait(uint id, string memory category) public {
      require(status_trait_swap ,"Trait Swap not Active!");
      require(_exists(id),"Invalid Token id!");
      require(ownerOf(id) == msg.sender, "Caller is not id owner!");
      require(IERC20(beatzAddress).balanceOf(msg.sender) >= swapPrice[category], "Insufficient balance to update trait!!");
      
      IERC20(beatzAddress).transferFrom(msg.sender, beatz_vault, swapPrice[category]);
      level[id] = level[id] + 1;
    }

    ///////////////////////////////////////////////////////////////////////////

    function numberMinted(address owner) public view returns (uint256) {
        return _numberMinted(owner);
    }

    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId),"ERC721Metadata: URI query for nonexistent token!");

        if(reveal)
            return bytes(baseURI()).length > 0 ? string(abi.encodePacked(baseURI(), tokenId.toString())) : "";
        else 
            return bytes(baseURI()).length > 0 ? baseURI() : "";
    }

    function baseURI() public view returns (string memory) {
        return uri;
    }

    function _startTokenId() pure internal override returns (uint256) {
        return 1;
    }

    function ownerTokens(address a) public view returns (uint[] memory){
        uint b = balanceOf(a);
        uint[] memory t= new uint[](b);
        for(uint i=0; i<b; i++) t[i] = tokenOfOwnerByIndex(a,i);
        return t;
    }

    function setApprovalForAll(address operator, bool approved) public override onlyAllowedOperatorApproval(operator) {
        super.setApprovalForAll(operator, approved);
    }

    function approve(address operator, uint256 tokenId) public override onlyAllowedOperatorApproval(operator) {
        super.approve(operator, tokenId);
    }

    function transferFrom(address from, address to, uint256 tokenId) public override onlyAllowedOperator(from) {
        super.transferFrom(from, to, tokenId);
    }

    function safeTransferFrom(address from, address to, uint256 tokenId) public override onlyAllowedOperator(from) {
        super.safeTransferFrom(from, to, tokenId);
    }

    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data)
        public
        override
        onlyAllowedOperator(from){
        super.safeTransferFrom(from, to, tokenId, data);
    }

    function withdrawMoney() external onlyOwner {
        (bool success, ) = msg.sender.call{value: address(this).balance}("");
        require(success, "Transfer failed.");
    }
}