using System;

namespace Fibonacci
{
	/// <summary>
	/// Summary description for Class1.
	/// </summary>
	/// 
	class Class1
	{
		static int fib (int n) 
		{
			if ( (n==1) || (n==2) ) 
			{
				return 1;
			}
			else 
			{
				return fib(n-1) + fib(n-2);
			}
		}
		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main(string[] args)
		{
			int num;
			string userNum;
			Console.WriteLine("Enter a number");
			userNum = Console.ReadLine();
			num = Int32.Parse(userNum);
			Console.WriteLine (fib(num));
		}
	}
}