interface IStrategyPool {
    // sell the amount of the input token, and the amount of output token will be sent to msg.sender
    function sellErc(address inputToken, address outputToken, uint256 inputAmt) external returns (uint256 outputAmt);

    function sellEth(address outputToken) external payable returns (uint256 outputAmt);
}
function sellErc(address inputToken, address outputToken, uint256 inputAmt) external returns (uint256 outputAmt);

// sell the amount of the input token, and the amount of output token will be sent to msg.sender