interface IERC20 {
 
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    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);

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

    event Approval(address indexed owner, address indexed spender, uint256 value);
}
function balanceOf(address account) external view returns (uint256);

/**
 * @dev Returns the amount of tokens owned by `account`.
 */