Contract Source Code:

// SPDX-License-Identifier: MIT

pragma solidity 0.8.19;

interface IERC20Errors {
    error ERC20InsufficientBalance(
        address sender,
        uint256 balance,
        uint256 needed
    );

    error ERC20InvalidSender(address sender);

    error ERC20InvalidReceiver(address receiver);

    error ERC20InsufficientAllowance(
        address spender,
        uint256 allowance,
        uint256 needed
    );

    error ERC20InvalidApprover(address approver);

    error ERC20InvalidSpender(address spender);
}

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;

    error OwnableUnauthorizedAccount(address account);

    error OwnableInvalidOwner(address owner);

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

interface IERC20 {
    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );

    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address to, uint256 value) external returns (bool);

    function allowance(
        address owner,
        address spender
    ) external view returns (uint256);

    function approve(address spender, uint256 value) external returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);
}

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);
}

abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
    mapping(address account => uint256) private _balances;

    mapping(address account => mapping(address spender => uint256))
        private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

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

    function name() public view virtual returns (string memory) {
        return _name;
    }

    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view virtual returns (uint256) {
        return _balances[account];
    }

    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }

    function allowance(
        address owner,
        address spender
    ) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(
        address spender,
        uint256 value
    ) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) public virtual returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }

    function _transfer(address from, address to, uint256 value) internal {
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(from, to, value);
    }

    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert ERC20InsufficientBalance(from, fromBalance, value);
            }
            unchecked {
                _balances[from] = fromBalance - value;
            }
        }

        if (to == address(0)) {
            unchecked {
                _totalSupply -= value;
            }
        } else {
            unchecked {
                _balances[to] += value;
            }
        }

        emit Transfer(from, to, value);
    }

    function _mint(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(address(0), account, value);
    }

    function _burn(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        _update(account, address(0), value);
    }

    function _approve(address owner, address spender, uint256 value) internal {
        _approve(owner, spender, value, true);
    }

    function _approve(
        address owner,
        address spender,
        uint256 value,
        bool emitEvent
    ) internal virtual {
        if (owner == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spender == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[owner][spender] = value;
        if (emitEvent) {
            emit Approval(owner, spender, value);
        }
    }

    function _spendAllowance(
        address owner,
        address spender,
        uint256 value
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            if (currentAllowance < value) {
                revert ERC20InsufficientAllowance(
                    spender,
                    currentAllowance,
                    value
                );
            }
            unchecked {
                _approve(owner, spender, currentAllowance - value, false);
            }
        }
    }
}


contract Advice_Dog is ERC20, Ownable {
    uint256 maxSupply = 1_000_000 * 1e18;

    constructor() ERC20("Advice Dog", "ADOG") Ownable(msg.sender) {
        _mint(msg.sender, maxSupply);
    }
}