#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <cmath>

#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <list>
#include <set>
#include <map>
using namespace std;

#define FOR(i,a,b) for(int i=(a); i<(b); ++i)
#define REP(i,n) for(int i=1; i<=(n); ++i)
#define pb push_back
#define INF 1000000001
#define EPS 10e-9
#define P 1000000007
typedef vector<int> vi;
typedef pair<int,int> pii;
#define st first
#define nd second
typedef long long ll;
typedef unsigned long long ull;
#define ISDEBUG 1
#define dprintf if(ISDEBUG) printf
void PTAB(const vi& t) {FOR(i,0,t.size()) printf("%d ", t[i]); puts("");}
#define DPTAB if(ISDEBUG) PTAB

char k[1001], p[100001];
int kn, pn;
#define M 26

int key(int i) {return k[i%kn];}

int main() {
	//dprintf("%d\n", 'Z'-'A');
	while(true) {
		scanf("%s", k);
		kn = strlen(k);
		if(kn == 1 && k[0]=='0') break;
		scanf("%s", p);
		pn = strlen(p);
		
		FOR(i,0,kn) k[i] -= 'A' - 1;
		FOR(i,0,pn) {
			p[i] -= 'A' - 1;
			p[i] += key(i);
			p[i] %= M;
			p[i] += 'A' -1;	
		}
		
		printf("%s\n", p);
		
		
		
	}
	return 0;
}