Code chef : ATM problem

// CODE: HS08TEST

// logic
//        the withdrawal amount should be a multiple of 5
//        the bank balance should not be equal to the
//         withdrawal amount because for every transaction
//         the bank charges 0.50 USD.

//         the withdrawal amount should be an int whereas
//         the bank balance and remaining balance after 
//         transaction should be float with 2 digits 
//        precision.

 #include <iostream>

int main()
{
    int x;
    float y;
    float z{0.5};
    std::cin >> x ;
    std::cin >> y ;
    if (x%5 == 0 && x<y && (x + 0.5) <= y)
    {
        std::cout << double(y - x - z);
    }
    else
    {
        std::cout << double(y);
    }

    return 0;
}