/*
 *      vigenere.java
 *      
 *      Copyright 2011 Contest Team 51 <cteam51@pc-221-52>
 *      
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *      
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *      
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *      MA 02110-1301, USA.
 */
import java.util.*;

public class vigenere {

	public static void main (String args[]) {		
	char[][] klice = new char[26][26];
	char pomo='B';
	for(int i=0;i<26;i++){
		
		for(int j=0;j<26;j++){
		  klice[i][j]=pomo;
		  if(pomo=='Z'){
			pomo='A';
			}else{ 
			pomo++;}
		
		}
	if(pomo=='Z'){
			pomo='A';
			}else 
			{
			pomo++;}
	}
	/*for (int i=0;i<26;i++){
		for(int j=0;j<26;j++){
			System.out.print(klice[i][j]+", ");		
		}
		System.out.println();
	}*/
	
	Scanner sc = new Scanner(System.in);
	
	String radek1=sc.nextLine();
	String radek2;
	while(radek1.compareTo("0")!=0){
		radek2=sc.nextLine();
		String novyRadek1="";
		String novyRadek2="";
		
		if(radek1.length()<radek2.length()){
			while(novyRadek1.length()<radek2.length()){
				novyRadek1+=radek1;
		
			}
			
			radek1=novyRadek1.substring(0,radek2.length());			
		} 
		
		else if(radek1.length()>radek2.length()){
			
			radek1=radek1.substring(0,radek2.length());
		
	
		}
	
	String vystup="";
	
	for(int i=0;i<radek2.length();i++){
		vystup+=klice[(int)(radek1.charAt(i))-65][(int)(radek2.charAt(i))-65];
	}
	System.out.println(vystup);
	
	radek1=sc.nextLine();
	}
	
	//System.out.println("ciselna hodnota a je"+(int)('A'));	
	}
}