using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Exer_CharityCompany
{
    class Program
    {
        static void Main(string[] args)
        {
            int days = int.Parse(Console.ReadLine());
            int bakers = int.Parse(Console.ReadLine());
            int cakes = int.Parse(Console.ReadLine());
            int wafles = int.Parse(Console.ReadLine());
            int pankes = int.Parse(Console.ReadLine());

            double totalcakesPrice = cakes * 45;
            double totalwaflesPrice = wafles * 5.80;
            double totalpankesPrice = pankes * 3.20;

            double totalSum = (totalcakesPrice + totalwaflesPrice + totalpankesPrice) * bakers;
            double finalMoney = totalSum * days;

            double totalMoney = finalMoney - (finalMoney / 8);

            Console.WriteLine("{0:F2}", totalMoney);

        }
    }
}