using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(F(8));

    }

    public static int F(int n)

    {

        if(n == 0) { return 0;}

        if(n == 1) { return 1;}

        else 

        {

            return F(n-1) + F(n-2);

        }

​

    }

}