input: Write a function that takes any number of integer arguments and returns their sum. 
  assert sum_ints(3, 5, 7) == 15
  assert sum_ints(1, 2, 3, 4) == 10
  assert sum_ints() == 0
  assert sum_ints(-1, -2, -3) == -6
  assert sum_ints(0) == 0
output: def sum_ints(*args):
      return sum(args)