input: Write a python function to perform parallel addition using multiprocessing.
  assert parallel_add(2, 3) == 5
  assert parallel_add(10, 15) == 25
  assert parallel_add(-1, 1) == 0
output: import multiprocessing
  
  def parallel_add(a, b):
      def add(x, y, result_queue):
          result_queue.put(x + y)
  
      result_queue = multiprocessing.Queue()
      process = multiprocessing.Process(target=add, args=(a, b, result_queue))
      process.start()
      process.join()
  
      return result_queue.get()