import java.math.*;
import java.io.*;

        
public class vigenere {

    public static void main(String[] args) throws Exception {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String line="";
        while(!"0".equals((line = in.readLine()))){
            char[] text = in.readLine().toCharArray();
            
            char[] key = line.toCharArray();
            int l = key.length;
            for (int i = 0; i < text.length; i++) {
                text[i] += key[i%l]-'A'+1;
                if (text[i]> 'Z') {
                    text[i] -= 26;
                }
            }
            System.out.println(new String(text));

            
        }
        
    }
    
}