class Program
{
    static void Main(string[] args)
    {
        double num = double.Parse(Console.ReadLine()!);
        int count = 0;
        double[] prime = { 2, 3, 5, 7, 11, 13 };
        double[] mix = { 4, 6, 8, 9, 10, 12 };

        for (int i = 0; i < prime.Length; i++)
        {
            for (int j = 0; j < mix.Length; j++)
            {
                if (prime[i] * mix[j] == num)
                {
                    count++;
                }
            }
        }

        double ans = count / 36.0;
        Console.WriteLine(ans);
    }
}