input: Write a function to calculate the sum of any number of integer arguments. The function should take a variable 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(1, -1, 2)==2
  assert sum_ints(0, 0, 0, 0)==0
  assert sum_ints() == 0
output: def sum_ints(*args):
      return sum(args)