// 
// File:   vigenere.cc
// Author: cteam59
//
// Created on November 13, 2011, 9:09 AM
//
#include <cstdio>
#include <cstdlib>
#include <cstring>

char alphabet[26]={'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};

int main(int argc, char** argv) {
    char key[1001], secret[100001];
    bool stop=false;
    int secretLen=0, keyLen=0;
    
    while(!stop)
    {
        scanf("%s", key);
        if(key[0]=='0' && key[1]=='\0')//koniec danych
        {
            stop = true;
            break;
        }
        scanf("%s", secret);
        
        secretLen = strlen(secret);
        keyLen = strlen(key);
        
        for(int i=0, j=0; i<secretLen; i++, j=(j+1)%keyLen)
        {
            //printf("%d ", secret[i]-65);
            //printf("%d ", (((secret[i]-65)+(key[j]-65)) %26 +2));
            
            secret[i]=alphabet[( ((secret[i]-65)+(key[j]-65)) %26 +1)%26];
            //printf("%d ", secret[i]-65);
        }
            printf("%s\n", secret);
    }
    
    return (0);
}