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


class Magatro
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        Console.WriteLine((1000000.0 - 100.0 * N) / (10000.0 + 98.0 * N));
    }
}