소프티어

import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int N = Integer.parseInt(br.readLine()); //8
        
        StringBuilder sb = new StringBuilder();
        
        for(int i = 0; i < N; i++){
            int Pi = 0;
            StringTokenizer st = new StringTokenizer(br.readLine(), " ");
            String Si = st.nextToken(); //Exit
            String Ti = st.nextToken(); //Alin

            for(int j = 0; j < Si.length(); j++){
                if(Si.charAt(j) == 'x' || Si.charAt(j) == 'X'){
                    Pi = j;
                    break;
                }
            }

            sb.append(Character.toUpperCase(Ti.charAt(Pi)));
        }
        String answer = sb.toString();

        System.out.println(answer);
        
    }
}