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

namespace YukiCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var   va = Console.ReadLine().Split();
            int    N = int.Parse(va[0]);
            double G = double.Parse(va[1]);
            double V = double.Parse(va[2]);
            var   nn = (N / 5) * G / V;
            Console.WriteLine(nn);
            Console.ReadLine();
        }
    }
}