// 
// File:   vigemere.cc
// Author: cteam21
//
// Created on November 13, 2011, 9:06 AM
//

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
//
// 
//
int main(int argc, char** argv) {
    char  key[1001];
    char plaintext[100001];
    int i, j, plainlength, keylength;
    char help;
    
    while (42){
        gets(key);
        if (key[0]=='0') return 0;
        gets (plaintext);
        keylength=strlen(key);
        plainlength=strlen(plaintext);
        i=j=0;
        for (;i<plainlength; i++){
            help=(key[j]-'A'+plaintext[i]-'A'+1)%26+'A';
            printf("%c", help);
            j++;
            if (j==keylength)j=0;
        }
        printf("\n");
    }
    
    return (0);
}