#include <cstdio>
#include <algorithm>
#include <string.h>

using namespace std; 

char Buffer1[1000000];
char Buffer2[1000000];

int ToInt(char c)
{
	return (c - 'A') + 1;
}

char ToChar(int c)
{
	if(c > 26)
	{
		c -= 26;
	}
	
	return (c + 'A') - 1;
}

int main()
{
	while(1)
	{
		scanf("%s", Buffer2);
		if(Buffer2[0] == '0')
		{
			break;
		}
		
		scanf("%s", Buffer1);
		int l = strlen(Buffer2);
		
		for(int i = 0; Buffer1[i]; i++)
		{
			printf("%c", ToChar(ToInt(Buffer1[i]) + ToInt(Buffer2[i % l])));
		}
		
		printf("\n");
	}
	
	return 0;
}