using System;

namespace UchebnaZala
{
    class Program
    {
        static void Main(string[] args)
        {

            double priceSkumriqKg = double.Parse(Console.ReadLine());
            double priceCacaKg = double.Parse(Console.ReadLine());
            double palamudKg = double.Parse(Console.ReadLine());
            double safridKg = double.Parse(Console.ReadLine());
            double midiKg = double.Parse(Console.ReadLine());


            double pricePalamud = (priceSkumriqKg * 1.6);
            double priceSafrid = (priceCacaKg * 1.8);
            double priceMidi = midiKg * 7.50;



            double palamudTotal = pricePalamud * palamudKg;

            double safridTotal = priceSafrid * safridKg;
            double midiTotal = priceMidi * midiKg;


            double totalPrice = palamudTotal + safridTotal + midiTotal;

            Console.WriteLine(Math.Round(totalPrice, 2));


        }
    }
}