using System;
using System.Linq;

public class Program {
    public static void Main() {
        int[] prime = {2, 3, 5, 7, 11, 13};
        int[] composite = {4, 6, 8, 9, 10, 12};
        int k = int.Parse(Console.ReadLine());
        int count = 0;
        foreach (int i in prime) {
            foreach (int j in composite) {
                if (i*j == k) count++;
            }
        }
        Console.WriteLine(count/36.0);
    }
}