interface StableSwapStEth {
    function get_virtual_price() external view returns (uint);

    /*
    0 ETH
    1 STETH
    */
    function balances(uint _index) external view returns (uint);

    function add_liquidity(uint[2] memory amounts, uint min) external payable;

    function remove_liquidity_one_coin(
        uint _token_amount,
        int128 i,
        uint min_amount
    ) external;
}
function balances(uint _index) external view returns (uint);

/*
 0 ETH
 1 STETH
 */