#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
string smi,sming,skey;
int main() {
	cin>>skey>>smi;
	int i,j,lens=smi.length();
	for(i=0; i<skey.length(); i++) {
		if(skey[i]<97)
			skey[i]-='A';
		else
			skey[i]-='a';
	}
	for(i=0; i<lens; i++) {
		char ch=smi[i]-skey[i%(skey.length()-1)];
		if((ch<'a'&&smi[i]<='z'&&smi[i]>='a')||(smi[i]<='Z'&&smi[i]>='A'&&ch<'A'))
			ch+=26;
		cout<<ch;
	}
	return 0;
}```