FibonacciNumbers

using System;

namespace FibonacciNumbers
{
    class Program
    {
        static void Main(string[] args)
        {
            var input = int.Parse(Console.ReadLine());
            Console.WriteLine(Fibonacci(input));
        }

        static int Fibonacci(int n)
        {
            if (n == 0 || n == 1) return 1;
            else return Fibonacci(n - 1) + Fibonacci(n - 2);
        }
    }
}