@Override
	public Integer call() throws Exception {
		int result = 1;
		if ((number == 0) || (number == 1)) {
			result = 1;
		} else {
			for (int i = 2; i <= number; i++) {
				result *= i;
				TimeUnit.MILLISECONDS.sleep(20);
			}
		}
		System.out.printf("%s: %d\n", Thread.currentThread().getName(), result);
		return result;
	}