input: Write a function to get the first two elements of a list.
  assert get_first_two([1, 2, 3, 4, 5]) == [1, 2]
  assert get_first_two([10, 20, 30, 40]) == [10, 20]
  assert get_first_two(['a', 'b', 'c', 'd']) == ['a', 'b']
output: def get_first_two(lst):
      return lst[:2]