Calculate Fibonacci sequence using recursive function in C#

static int Fibonacci (int x)
{
   Console.WriteLine ("x = {0}", x);
   if (x <= 1)
   {
      return 1;
   }
   return Fibonacci (x-1) + Fibonacci (x-2);
}

static void Main( )

{

   Console.WriteLine ("Fibonacci no. = {0}", Fibonacci (5));

   Console.ReadKey();
}