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

char shift (char a, char b) {
	int res = a + b - 64;
	if (res > 90) {
		res %= 90;
		res += 64;
	}
	return res;
}

int main (int argc, char ** argv) {
	while (1) {
		char key[1001] = "";
		char msg[100001] = "";
		char msg2[100001]= "";
		scanf ("%s\n", key);
		if (!strcmp(key, "0")) return 0;
		scanf("%s\n", msg);
		int kLen = strlen(key);
		int mLen = strlen(msg);
		int i;
		for (i=0;i<mLen;i++) {
			msg2[i] = shift(msg[i], key[i%kLen]);
		}
		printf("%s\n", msg2);
	}
	return 0;
}