using System;

​

public class Program

{

    public static void Main()

    {

        int lenght = int.Parse(Console.ReadLine());

        int width = int.Parse(Console.ReadLine());

        int height = int.Parse(Console.ReadLine());

        double percent = double.Parse(Console.ReadLine());

        double sum = (lenght * 1.00 / 10) * (width * 1.00 / 10) * (height * 1.00 / 10);

        double all = sum * (1 - percent / 100);

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

    }

}