using System;

public class Hello
{
    public static void Main()
    {
        var s = "142857";
        var n = int.Parse(Console.ReadLine().Trim());
        if (n == 0) { Console.WriteLine(0); goto end; }
        var a1 = n / 6;
        var a2 = n % 6;
        Console.Write("0.");
        for (int i = 0; i < a1; i++) Console.Write(s);
        Console.WriteLine(s.Substring(0,a2));
        end:;
    }
}