public static void main(String args[]) throws Exception {
        ExecutorService pool = Executors.newFixedThreadPool(4);
        Set<Future<Integer>> set = new HashSet<Future<Integer>>();
        String[] args1 = "13 12 12 14".split(" ");
        for (String word: args1) {
            Callable<Integer> callable = new WordLengthCallable(word);
            Future<Integer> future = pool.submit(callable);
            set.add(future);
        }
        int sum = 0;
        for (Future<Integer> future : set) {
            sum += future.get();
        }
        System.out.printf("The sum of lengths is %s%n", sum);
        System.exit(sum);
    }