#include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;
char k[110],s[1100],ans[1100];
int get(char a)
{
	if('A'<=a&&a<='Z') return a-'A';
	else return a-'a';
}
int main()
{
	freopen("vigenere.in","r",stdin);
	freopen("vigenere.out","w",stdout);
	scanf("%s",k);
	scanf("%s",s);
	int mod=strlen(k);
	char tem;
	for(int i=0;i<strlen(s);i++)
	{
		int now=(get(s[i])-get(k[i%mod])+26)%26;
		if(s[i]-'A'>25) tem='a';
		else tem='A';
		ans[i]=tem+now;
	}
	printf("%s",ans);
	return 0;
}