using System;

namespace Fish_Tank
{
    class Program
    {
        static void Main(string[] args)
        {
            int lenght = int.Parse(Console.ReadLine());
            int width = int.Parse(Console.ReadLine());
            int height = int.Parse(Console.ReadLine());
            double percent = double.Parse(Console.ReadLine());

            int volume = lenght * width * height;
            double literVolume = volume / 1000d;
            double busyVolume = percent / 100d;


            double neededLiters = literVolume - (literVolume * busyVolume);
            Console.WriteLine(neededLiters);


        }
    }
}