#include<stdio.h>
#include<string.h>
int main()
{
	char word[1001],key[101];
	scanf("%s",key);
	scanf("%s",word);
	int i=0,j=0,len=strlen(key);
	while(word[i])
	{
		char c=key[j++%len],c2;
		if(c>='a'&&c<='z')
		{
			c2=word[i]-c+'a';
		}
		else
		{
			c2=word[i]-c+'A';
		}
		if(word[i]>='A'&&word[i]<='Z')
		{
			if(c2<'A')
			{
				printf("%c",c2+26);
			}
			else
			{
				putchar(c2);
			}
		}
		else if(word[i]>='a'&&word[i]<='z')
		{
			if(c2<'a')
			{
				printf("%c",c2+26);
			}
			else
			{
				putchar(c2);
			}
		}
		i++;		
	}
}