input: Write a python function to print the first 5 elements of a list.
  assert first_five_elements([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == [1, 2, 3, 4, 5]
  assert first_five_elements([10, 20, 30, 40, 50, 60, 70, 80, 90, 100]) == [10, 20, 30, 40, 50]
  assert first_five_elements([5, 7, 9, 8, 6, 4, 3]) == [5, 7, 9, 8, 6]
output: def first_five_elements(lst):
      return lst[:5]