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 = [64, 34, 25, 12, 22, 11, 90]
      >>> insertion_sort(arr)
      >>> arr
      [11, 12, 22, 25, 34, 64, 90]
      
      >>> insertion_sort([5, 4, 3, 2, 1])
      >>> arr
      [1, 2, 3, 4, 5]
      """
      for i in range(1, len(arr)): 
          key = arr[i] 
    
          # Move elements of arr[0..i-1], 
          # that are greater than key, 
          # to one position ahead of 
          # their current position 
          j = i-1
          while j >= 0 and key < arr[j] : 
                  arr[j + 1] = arr[j] 
                  j -= 1
          arr[j + 1] = key
output:     for i in range(1, len(arr)): 
          key = arr[i] 
    
          # Move elements of arr[0..i-1], 
          # that are greater than key, 
          # to one position ahead of 
          # their current position 
          j = i-1
          while j >= 0 and key < arr[j] : 
                  arr[j + 1] = arr[j] 
                  j -= 1
          arr[j + 1] = key