public static void main(String[] args) {
        String[] listStr={"k","ab","a","kie","kit","kitt","kittty"};
        HashMap<String,Integer> map=new HashMap<>();
        for(String str:listStr){
            map.put(str,1);
        }
        PriorityQueue<String> priorityQueue=new PriorityQueue<>((a,b)->b.length()-a.length());
        for(String str:listStr){
            int endSize=0;
            for(int i=1;i<=str.length();i++){
                String curStr=str.substring(0,i);
                if(map.containsKey(curStr)){
                    endSize++;
                }
            }
            if(endSize==str.length()){
                priorityQueue.add(str);
            }
        }
        System.out.println(priorityQueue.peek());
    }