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

namespace Distance
{
    class Distance
    {
        static void Main(string[] args)
        {
            double a = double.Parse(Console.ReadLine());
            double b = double.Parse(Console.ReadLine());
            double c = double.Parse(Console.ReadLine());
            double d = double.Parse(Console.ReadLine());


            double aKm = a *(b / 60); // purvo

            double aAfter = a + (10 * a / 100);
            double bKm = aAfter * (c / 60); // vtoro

            double cPercent = aAfter - (5 * aAfter / 100);
            double cKm = cPercent * (d / 60); // treto

            double total = aKm + bKm + cKm;
            Console.WriteLine("{0:f2}",total);




            //var pyrvo = a * (b / 60);
            //var vtoro = (a + (a * 0.1)) * (c / 60);
            //var treto = ((a + (a * 0.1)) -( a * 0.05)) * (d / 60);
            //var l = pyrvo + vtoro + treto;
            //Console.WriteLine("{0:f2}", l);


        }
    }
}