input: 
  def calculate_fibonacci(n: int) -> int:
      """ Calculate the Fibonacci number up to a given number using a recursive approach.
      >>> calculate_fibonacci(0)
      0
      >>> calculate_fibonacci(1)
      1
      >>> calculate_fibonacci(10)
      55
      """
      if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return calculate_fibonacci(n - 1) + calculate_fibonacci(n - 2)
  
output:     if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return calculate_fibonacci(n - 1) + calculate_fibonacci(n - 2)