input: Write a function to take any number of integer arguments and return their sum. If no arguments are provided, the function should return 0.
  assert sum_ints(3, 5, 7)==15
  assert sum_ints()==0
  assert sum_ints(10, -5, 2)==7
  assert sum_ints(8, 8, 8, 8)==32
output: def sum_ints(*args):
      return sum(args)