input: def print_unique(my_list):
      """Prints the unique elements of a given list.
      >>> print_unique([1, 2, 2, 3, 4, 4, 5])
      1
      2
      3
      4
      5
      >>> print_unique([1, 1, 1, 1])
      1
      """
output:     unique_elements = set(my_list)
      for element in sorted(unique_elements):
          print(element)