input: 
  def calculate_square_root(n: float) -> float:
      """ Calculate and return the square root of a positive number.
      >>> calculate_square_root(100)
      10.0
      >>> calculate_square_root(25.0)
      5.0
      """
  
output:     if n < 0:
          raise ValueError("Input must be a non-negative number")
      return n ** 0.5