using System.Text;
using System;

public class Hello
{
    public static void Main()
    {
        var sb = new StringBuilder();
        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;
        sb.Append("0.");
        for (int i = 0; i < a1; i++) sb.Append(s);
        sb.Append(s.Substring(0, a2));
        sb.Append("\n");
        Console.Write(sb);
        end:;
    }
}