input: Write a function that takes any number of integer arguments and returns their sum. If no arguments are provided, the function should return 0.
  assert sum_ints(3, 5, 7)==15
  assert sum_ints(1, 2, 3, 4, 5)==15
  assert sum_ints() == 0
  assert sum_ints(-1, -2, -3)==-6
  assert sum_ints(10, -10, 20, -20) == 0
output: def sum_ints(*args):
      return sum(args)