Fibonacci Number

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

namespace Fibonacci
{
    public class Program
    {
        private static long CalculateFibonacci(long n)
        {
            if (n == 0) return 0;
            if (n == 1) return 1;
            return CalculateFibonacci(n - 1) + CalculateFibonacci(n - 2);
        }

        static int Main(string[] args)
        {
            long number = 0;

            Console.WriteLine("Enter a small positive natural number");
            Console.WriteLine("It is better you enter a number lower than 48");

            try
            {
                Console.Write("Enter the number: ");
                number = long.Parse(Console.ReadLine());

                Console.WriteLine("Fibonacci of {0} is {1}", number,
				 CalculateFibonacci(number));
            }
            catch (FormatException)
            {
                Console.WriteLine("Invalid Value!");
            }
            catch (Exception)
            {
                Console.WriteLine("Something went wrong");
            }

            return 0;
        }
    }
}