using System;

namespace yukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
            double a = double.Parse(Console.ReadLine());
            double[] b = {2,3,5,7,11,13 };
            double[] c = { 4, 6, 8, 9, 10, 12 };
            double ans = 0;
            double count = 0;
            double sum = 0;
            for (int i = 0; i < 6; i++)
            {
                for(int j = 0; j < 6; j++)
                {
                    sum = b[i] * c[j];
                    if (sum==a)
                    {
                        count++;
                    }
                }
            }
            ans = count / 36;
            Console.WriteLine(ans);
        }
    }
}