input: def calculate_average(nums: List[int]) -> float:
      """
      Calculate the average of a list of five numbers.
      
      >>> calculate_average([1, 2, 3, 4, 5])
      3.0
      >>> calculate_average([10, 20, 30, 40, 50])
      30.0
      """
      average = sum(nums) / len(nums)
      return average
output:     average = sum(nums) / len(nums)
      return average