input: from typing import List
  
  def sum_sequence(sequence: List[int]) -> int:
      """
      Calculate the sum of a given sequence of integers.
      >>> sum_sequence([1, 2, 3, 4, 5])
      15
      >>> sum_sequence([-1, 0, 1])
      0
      """
      sum_ = 0
      for num in sequence:
          sum_ += num
      return sum_
output:     sum_ = 0
      for num in sequence:
          sum_ += num
      return sum_