input: def add_marks(marks: list, mark: int) -> list:
      """ Add the integer 'mark' to each value in the list 'marks'.
      >>> add_marks([87, 56, 99, 54], 4)
      [91, 60, 103, 58]
      """
output:     for i in range(len(marks)):
          marks[i] += mark
      return marks