public static void main(String[] args) {

		if (args.length == 0 || (args.length == 1 && args[0].equals("-i"))) {

			Runnable task = new CalculatorInteractive();
			task.run();

		} else if (args.length == 1) {

			Runnable task = new CalculatorBatch(new File(args[0]));
			task.run();

		}

	}