input: Write a function to take any number of integer arguments and return their sum. If no arguments are provided, return 0 as the default sum.
  assert sum_ints(3, 5, 7)==15
  assert sum_ints(1, 2, 3, 4, 5)==15
  assert sum_ints()==0
  assert sum_ints(10, -5, 8)==13
  assert sum_ints(0, 0, 0, 0)==0
output: def sum_ints(*args):
      return sum(args)