Fibonacci Number According To Its Position

using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Numerics;

namespace SoftuniExercisesWithVariables
{
    class Program
    {
        static void Main(string[] args)
        {

            Console.WriteLine("Enter the wanted fibonacci number: ");
            int count = int.Parse(Console.ReadLine());
            int firstNum = 1;
            int secondNum = 1;
            int thirdNum = 0;
            List<int> numbers = new List<int> { 1, 1 };
            for(int i = 2; i < count/2; i++)
            {
                thirdNum = firstNum + secondNum;
                numbers.Add(thirdNum);
                firstNum = secondNum + thirdNum;
                numbers.Add(firstNum);
                secondNum = firstNum + thirdNum;
                numbers.Add(secondNum);
            }

            numbers.ToArray();
            Console.WriteLine(numbers[count-1]);
        }
    }
}