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

namespace CharityCampaign
{
    class CharityCampaign
    {
        static void Main(string[] args)
        {
            int campaignDays = int.Parse(Console.ReadLine());
            int bakers = int.Parse(Console.ReadLine());
            int cakes = int.Parse(Console.ReadLine());
            int gofrets = int.Parse(Console.ReadLine());
            int pancakes = int.Parse(Console.ReadLine());

            double cakeSum = cakes * 45;
            double gofretsSum = gofrets * 5.80;
            double pancakesSum = pancakes * 3.20;

            double sum = (cakeSum + gofretsSum + pancakesSum) * bakers * campaignDays;
            double leftSum = sum * 0.125;

            Console.WriteLine("{0:F2}", sum - leftSum);
        }
    }
}