input: Write a function to find the nth Fibonacci number. The function should return the nth Fibonacci number if n is positive. If n is 0, the function should return 0. If n is 1, the function should return 1. For any other negative input, the function should print "Incorrect input".
  def Fibonacci(n): 
      if n<0: 
          print("Incorrect input") 
      elif n==0: 
          return 0
      elif n==1: 
          return 1
      else: 
          return Fibonacci(n-1)+Fibonacci(n-2)
  assert Fibonacci(0)==0
  assert Fibonacci(1)==1
  assert Fibonacci(5)==5
  assert Fibonacci(10)==55
output: def Fibonacci(n): 
      if n<0: 
          print("Incorrect input") 
      elif n==0: 
          return 0
      elif n==1: 
          return 1
      else: 
          return Fibonacci(n-1)+Fibonacci(n-2)