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

#define MAX1 1000
#define MAX2 100100


char s1[MAX1], s2[MAX2];

char ch(char z, char p)
{
	int a=z-'A';
	int b=p-'A'+1;
	return (a+b)%26+'A';
}

int main()
{
	while(gets(s1), strcmp(s1,"0"))
	{
		gets(s2);
		int j=0;
		for(int i=0; i<(int) strlen(s2); i++)
		{
			j = j % strlen(s1);
			s2[i] = ch(s2[i], s1[j]);
			j++;
		}
		puts(s2);
	}
	return 0;
}