Fibonacci C#

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

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

            int f0 = 0;
            int f1 = 1;
            int fN = 0;
            int n = int.Parse(Console.ReadLine());
            do
            {
                fN = f0 + f1;
                f0 = f1;
                f1 = fN;
                ;

                n--;

            }
            while (n > 0);

            Console.WriteLine(f1);
            Console.ReadLine();
        }
    }
}