input: Write a function to calculate the Fibonacci numbers up to a given number. The function should return the nth Fibonacci number where n is the number provided. If the number provided is 0, the function should return 0, and if it is 1, the function should return 1. For any other number, the function should 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(2)==1
  assert Fibonacci(3)==2
  assert Fibonacci(4)==3
output: def Fibonacci(n): 
  	if n==0: 
  		return 0
  	if n==1: 
  		return 1
  	else: 
  		return Fibonacci(n-1)+Fibonacci(n-2)