import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;


public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);
        final String key = sc.nextLine();
        final String text = sc.nextLine();
        final StringBuilder sb = new StringBuilder();
        final char[] chars = new char[text.length()/2];
        for (int i = 0; i < text.length(); i += 2) {
            chars[i/2] = (char)(key.charAt(i/2%key.length()) ^ (char)Long.parseLong(text.substring(i, i+2), 16));
        }
        System.out.println(new String(chars));
    }
    
}