#include <stdio.h>
#include <string.h>

char key[2000];
char msg[200000];

void rmnl(char *s)
{
	while (*s) {
		if (*s == '\n') {
			*s = 0;
			break;
		}
		s++;
	}
}

int main(void)
{
	int keylen, msglen, i;
	while (1) {
		fgets(key, 2000, stdin);
		if (key[0]=='0') break;
		fgets(msg, 200000, stdin);
		rmnl(key);
		keylen = strlen(key);
		msglen = strlen(msg);
		for (i=0; i<msglen; i++) {
			if (msg[i] > 'Z' || msg[i] < 'A') continue;
			/*printf("%d",i%keylen);*/
			msg[i] = (msg[i] - 'A' + key[i%keylen] - 'A' + 1) % 26 + 'A';
		}
		fputs(msg, stdout);
	}
	return 0;
}