using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yukicoderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            int k = int.Parse(input);
            int[] sosuu = { 2, 3, 5, 7, 11, 13 };
            int[] gousei = { 4, 6, 8, 9, 10, 12 };
            double cnt = 0;
            for(int i=0;i<sosuu.Length;i++)
            {
                for(int j=0;j<gousei.Length;j++)
                {
                    if(sosuu[i]*gousei[j]==k)
                    {
                        cnt++;
                    }
                }
            }
            Console.Write(cnt / 36);
        }

    }
}