Bar

# include <iostream>
using namespace std;
#include <iomanip>
#include <math.h>
#include <cmath>

int main()
{
    double whiskeyprice;
    cin >> whiskeyprice;
    double beer;
        do
    {
        cin.clear();
        cin >> beer;
    }
    while (cin.bad() || beer < 0 || beer> 10000);
    double wine;
    do
    {
        cin.clear();
        cin >> wine;
    } while (cin.bad() || wine < 0 || wine> 10000);
    double brandy;
    do
    {
        cin.clear();
        cin >> brandy;
    } while (cin.bad() || brandy< 0 || brandy > 10000);
    double whiskey;
    do
    {
        cin.clear();
        cin >> whiskey;
    } while (cin.bad() || whiskey < 0 || whiskey> 10000);
    double brandyprice = whiskeyprice / 2;
    double wineprice = brandyprice *0.6;
    double beerprice = brandyprice * 0.2;
    double sum = beerprice*beer + wineprice*wine + brandyprice*brandy + whiskeyprice*whiskey;

    cout << fixed << setprecision(2) << sum << endl;


    return 0;
    }