input: 
  from typing import List
  
  
  def calculate_sum(numbers: List[int]) -> int:
      """ Calculate the sum of the given list of integers.
      >>> calculate_sum([1, 2, 3])
      6
      >>> calculate_sum([-1, 0, 1])
      0
      """
  
output:     total = 0
      for num in numbers:
          total += num
      return total