I tested it, it worked for sure:

    public static void main(String[] args) {
        String str = "hellllllloooo";
        System.out.println(clever(str));
        String str1 = "hi";
        System.out.println(clever(str1));
        String str2 = "";
        System.out.println(clever(str2));

    }
 
 #########oooo
hi