Fibonachy algorithm

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _08._Recursive_Fibonacci
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());


            int result = Fibonachi(n);


            Console.WriteLine(result);

        }

        public static int Fibonachi(int num)
        {
            int result = 0;
            int firstNum = 1;
            int secondNum = 1;
            for (int i = 3; i <= num; i++)
            {

                result = firstNum + secondNum;

                int temp = secondNum;
                secondNum = result;
                firstNum = temp;
            }


            if (firstNum == 0 || secondNum == 1)
            {



                return firstNum;
            }
            return Fibonachi(num-1)+Fibonachi(num-2);

        }
    }
}