input: def Fibonacci(n: int) -> int:
      """
      Find the nth Fibonacci number. If the input is less than 0, print an error message.
      
      >>> Fibonacci(0)
      0
      >>> Fibonacci(1)
      1
      >>> Fibonacci(5)
      5
      """
      if n < 0:
          print("Incorrect input")
      elif n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return Fibonacci(n - 1) + Fibonacci(n - 2)
output:     if n < 0:
          print("Incorrect input")
      elif n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return Fibonacci(n - 1) + Fibonacci(n - 2)