Smart Contract for depositing Eth into Compound

zap.sol

pragma solidity ^0.5.0;

interface CtokenInterface {
function mint() external payable;
function transfer(address, uint256) external returns (bool);
function balanceOf(address owner) external view returns (uint256);
}

contract Zap{
address cEthAddress = 0xf92FbE0D3C0dcDAE407923b2Ac17eC223b1084E4;
CtokenInterface cEth = CtokenInterface(cEthAddress);

function deposit() external payable {
cEth.mint.value(msg.value)();
    }
}