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

public class P0211 {
    public static void Main() {
        var k = int.Parse(Console.ReadLine().Trim());
        var cands = new List<int>();
        var primes = new int[]{2,3,5,7,11,13};
        var comps = new int[]{4,6,8,9,10,12};
        for(int i=0; i<6; i++) {
            for(int j=0; j<6; j++) {
                cands.Add(primes[i] * comps[j]);
            }
        }
        Console.WriteLine(cands.Where(c => c == k).Count() / 36.0);
    }
}