input: Write a function to calculate the Fibonacci numbers up to a given number `n`. If `n` is 0, return 0. If `n` is 1, return 1. For any other value of `n`, return the sum of the two preceding Fibonacci numbers.
  
  def Fibonacci(n): 
  	if n==0: 
  		return 0
  	if 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: 
  		return 0
  	if n==1: 
  		return 1
  	else: 
  		return Fibonacci(n-1)+Fibonacci(n-2)