using System;

​

public class Program

{

    static Random rand = new Random();

    public static int sim()

    {

        int prev = -1;

        for (int i = 1; ; i++)

        {

            int curr = rand.Next(2);

            if (curr == 0 && prev == 0)

            {

                return i;

            }

            prev = curr;

        }

    }

    public static void Main()

    {

        int n = 1000000;

        double s = 0.0, ss = 0.0;

        for (int i = 0; i < n; i++)

        {

            int x = sim();

            s += x;

            ss += x*x;

        }

        double sm = s/n;

        double sv = (ss - s*s/n)/(n-1);

        Console.WriteLine("Sample Mean = " + sm);

        Console.WriteLine("Sample Variance = " + sv);

    }

}