input: 
  def insertion_sort(lst: List[int]) -> List[int]:
      """ Sorts a list of integers using the insertion sort algorithm.
      >>> insertion_sort([4, 2, 7, 1, 3])
      [1, 2, 3, 4, 7]
      >>> insertion_sort([9, 7, 5, 3, 1])
      [1, 3, 5, 7, 9]
      """
  
output:     for i in range(1, len(lst)):
          key = lst[i]
          j = i - 1
          while j >= 0 and lst[j] > key:
              lst[j + 1] = lst[j]
              j -= 1
          lst[j + 1] = key
      return lst