input: def accumulate_up_to_n(n: int):
      """accumulate_up_to_n is a function that calculates the sum of integers from 1 to n.
      >>> accumulate_up_to_n(30)
      465
      >>> accumulate_up_to_n(100)
      5050
      >>> accumulate_up_to_n(5)
      15
      >>> accumulate_up_to_n(10)
      55
      >>> accumulate_up_to_n(1)
      1
      """
output:     return sum(range(1, n + 1))