input: Write a python function to compare the lengths of two lists and print the shorter one.
  assert compare_lists([1, 2, 3], [4, 5]) is None
  assert compare_lists([1, 2], [3, 4, 5, 6]) is None
  assert compare_lists([], [1, 2, 3]) is None
output: def compare_lists(list1, list2):
      if len(list1) < len(list2):
          print(list1)
      else:
          print(list2)