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());
     
    String[] sArr = new String[N];
    String[] tArr = new String[N];

    StringBuilder resultSb = new StringBuilder();

    for(int i=0; i<N; i++) {
      String[] inputArr = br.readLine().split(" ");
      sArr[i] = inputArr[0].toUpperCase();
      tArr[i] = inputArr[1].toUpperCase();
    }

    for(int i=0; i<N; i++) {
      resultSb.append(tArr[i].charAt(sArr[i].indexOf("X")));
    }

    System.out.print(resultSb);
  }
}