interface CErc20 {
    function balanceOf(address _owner) external view returns (uint);
    //function balanceOfUnderlying(address owner) external returns (uint);
    function balanceOfUnderlying(address owner) external view returns (uint);
    function mint(uint mintAmount) external returns (uint);
    function redeemUnderlying(uint redeemAmount) external returns (uint);
    function redeem(uint redeemAmount) external returns (uint);
    function exchangeRateStored() external view returns (uint);
}
function balanceOfUnderlying(address owner) external view returns (uint);

//function balanceOfUnderlying(address owner) external returns (uint);