input: Write a function to generate the nth Fibonacci number using recursion.
  assert Fibonacci(1) == 0
  assert Fibonacci(2) == 1
  assert Fibonacci(3) == 1
  assert Fibonacci(4) == 2
  assert Fibonacci(5) == 3
  assert Fibonacci(9) == 21
output: def Fibonacci(n):
      if n == 1:
          return 0
      elif n == 2:
          return 1
      else:
          return Fibonacci(n - 1) + Fibonacci(n - 2)