#include <cstdio>
#include <cstring>
using namespace std;

char k[1042], p[100042];

int main() {
	while (1) {
		gets(k);
		if (k[0] == '0') break;
		gets(p);
		int klen = strlen(k), plen = strlen(p);
		for (int i = 0; i < plen; ++i) {
			int kk = k[i%klen]-'A'+1;
			int pp = p[i]-'A';
			pp = (pp+kk)%26;
			putchar('A'+pp);
		}
		putchar('\n');
	}
	return 0;
}