using System;

namespace Supplies_for_School
{
    class Program
    {
        static void Main(string[] args)
        {
            int pensQuantity = int.Parse(Console.ReadLine());
            int markersQuantity = int.Parse(Console.ReadLine());
            int preparQuantity = int.Parse(Console.ReadLine());
            int percentDiscount = int.Parse(Console.ReadLine());



            double pensPrice = pensQuantity * 5.80;
            double markersPrice = markersQuantity * 7.20;
            double preparPrice = preparQuantity * 1.20;
            double discount = 0.25;



            double materialsSum = pensPrice + markersPrice + preparPrice;
            double discountSum=   materialsSum- (materialsSum*discount);










            Console.WriteLine(discountSum);


        }
    }
}