public static String canConstruct(List<Integer> a) {
        int res = 0;

        for (Integer i : a) {
            char[] charArray = String.valueOf(i).toCharArray();
            for (char c : charArray) {
                res += Integer.parseInt(Character.toString(c));
            }
        }
        return (res % 3 == 0)? "Yes" : "No";
    }