input: from typing import List
  
  def insertion_sort(arr: List[int]) -> None:
      """Sorts a list of n distinct integers in-place using the insertion sort algorithm.
      >>> arr = [3, 2, 1]
      >>> insertion_sort(arr)
      >>> arr
      [1, 2, 3]
      >>> arr = [4, 3, 5, 1, 2]
      >>> insertion_sort(arr)
      >>> arr
      [1, 2, 3, 4, 5]
      """
output:     for i in range(1, len(arr)):
          key = arr[i]
          j = i - 1
          while j >= 0 and arr[j] > key:
              arr[j + 1] = arr[j]
              j -= 1
          arr[j + 1] = key