public static void main(String[] args) {
        String incoming = "AABBBBCCDDDDDMMVG";
        StringBuilder b = new StringBuilder();

        if (incoming == null || incoming.isEmpty()) {
            return;
        }

        char[] chars = incoming.toCharArray();
        char prev = chars[0];
        int counter = 1;

        for (int i = 1; i < chars.length; i++) {
            char current = chars[i];
            if (current != prev) {
                b.append(prev).append(counter);
                prev = current;
                counter = 1;
            } else {
                counter++;
            }
        }
        b.append(prev).append(counter);
        System.out.println(b.toString());
    }