public class Test{
        public static void main(String args[]){
        String string="3443";
                System.out.println(sum("11122"));
        System.out.println(sum(string));
    }
    public static String sum(String str){
        StringBuffer string=new StringBuffer();
        
        while(str.length()>0){
            int length=str.length();
            String s=str.substring(0,1);
            str=str.replaceAll("^"+s+"+", "");
            string.append(s);
            string.append(length-str.length());
        }
        
        return string.toString();
    }
}