View Code of Problem 2591

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        int t=Integer.parseInt(scanner.nextLine());
        while(t-->0){
            String s1=scanner.nextLine();
            String s2=scanner.nextLine();
            StringBuilder ans=new StringBuilder();
            List<Character> characterList=new ArrayList<>();
            for(char c:s2.toCharArray()){
                characterList.add(c);
            }
            List<Character> list=new ArrayList<>();
            for(char c:s1.toCharArray()){
                if(characterList.contains(c)){
                    list.add(c);
                    characterList.remove(characterList.indexOf(c));
                }
            }
            Collections.sort(list);
            if(list.size()==0){
                ans.append("-1");
            }
            else{
                for (char c : list) {
                    ans.append(c);
                }
            }

            System.out.println(ans);
        }
    }

}