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());

            int CakeSum = Cakes * 45;
            double GofretsSum = Gofrets * 5.80;
            double PancakesSum = Pancakes * 3.20;

            double Sum = (CakeSum + GofretsSum + PancakesSum) * Bakers;
            double LeftSum = Sum/0.125;

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