public class ConsecutiveSolution {
    public static int consecutive(int n) {
        String digs = Integer.toString(n);
        for (int i = 1; i < digs.length(); i++) {
            if (digs.charAt(i) == digs.charAt(i - 1)) {
                return i;
            }
        }
        return -1;
    }

    public static int solution(int n) {
        int culprit = consecutive(n);
        if (culprit >= 1) {
            char[] digs = Integer.toString(n).toCharArray();

            if (digs[culprit] <= '8') {
                digs[culprit] += 1;
                int dig = 0;
                for (int i = culprit + 1; i < digs.length; i++) {
                    digs[i] = (char) (dig + '0');
                    dig = (dig + 1) % 2;
                }
                return Integer.parseInt(new String(digs));
            } else {
                return solution(n + (int) Math.pow(10, digs.length - culprit - 1));
            }
        } else {
            culprit = consecutive(n + 1);
            return culprit == -1 ? n + 1 : solution(n + 1);
        }
    }

    public static void main(String[] args) {
        int n = 12345; // Your input number
        int result = solution(n);
        System.out.println(result);
    }
}