input: Write a python function to get the last element of a list.
  assert get_last_element([1, 8, 3, 10, 5]) == 5
  assert get_last_element([10, 20, 30, 40, 50]) == 50
  assert get_last_element([7, 14, 21, 28]) == 28
output: def get_last_element(lst):
      return lst[-1]