#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cmath>
#include <cstring>
using namespace std;
#define REP(i,a,b) for (int i = (a); i <= (b); ++i)
#define FORI(i,n) REP(i,1,n)
#define FOR(i,n) REP(i,0,int(n)-1)
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define vi vector<int>
#define ll long long
#define SZ(x) ((int)(x.size()))
#define IN(x,y) ((y).find((x)) != (y).end())
#define DBG(v) cerr << #v << " = " << (v) << endl;
#define FOREACH(i,t) for (typeof (t.begin()) i = t.begin(); i != t.end(); i++)
#define fi first
#define se second

char s[100007], text[100007];

char cipher (char a, char b) {
	char c = a + b - 'A' + 1;
	if (c > 'Z') c = c - 'Z' + 'A' - 1;
	return c;
}

int main () {
/*	DBG(cipher('A','A'))
	DBG(cipher('A','B'))
	DBG(cipher('A','Y'))
	DBG(cipher('A','Z'))
	DBG(cipher('B','Y'))
	DBG(cipher('Z','Z'))*/
	while(1) {
		scanf("%s",s);
		if (strcmp(s,"0") == 0) break;
		int slen = strlen(s);
		scanf("%s", text);
		
		for (int i = 0; text[i]; ++i) {
			text[i] = cipher(text[i], s[i % slen]);
		}
		
		printf("%s\n",text);
	}
	return 0;
}