int x = 0;
        int count = 0;
        int result = 0;
        for (int i = 0; i < a.size(); i++) {
            x = a.get(i);
            for (int j = 0; j < a.size(); j++) {

                if (x + 1 == a.get(j) || x == a.get(j))
                    count++;

                if (count > result) result = count;
            }
            count = 0;
        }
        return result;