String readoff(String s) {
		int m = s.length();
		StringBuilder sb = new StringBuilder();
		char cur = s.charAt(0);
		int count = 1;
		for (int i = 1; i < m; i++) {
			if (s.charAt(i) != cur) {
				sb.append(count);
				sb.append(cur);
				count = 1;
				cur = s.charAt(i);
			} else {
				count++;
			}
		}
		sb.append(count);
		sb.append(cur);

		return sb.toString();
	}