input: Write a python function to add five to each element in a list.
  assert add_five([1, 2, 3, 4, 5]) == [6, 7, 8, 9, 10]
  assert add_five([10, 15, 20]) == [15, 20, 25]
  assert add_five([0, -5, -10]) == [5, 0, -5]
output: def add_five(lst):
      return [x + 5 for x in lst]