input: Write a function to calculate the sum of multiples of 8 in a list.
  assert sum_multiples([4, 8, 12, 17, 30]) == 20
  assert sum_multiples([16, 24, 32, 40, 5]) == 112
  assert sum_multiples([1, 2, 3, 4, 5, 6, 7, 9, 10]) == 0
output: def sum_multiples(lst):
      return sum(x for x in lst if x % 8 == 0)