#include<fstream>
#include<string>
using namespace std;
int main(){
	ifstream fin("vigenere.in");
	ofstream fout("vigenere.out");
	string a,b;
	int i,x,y,p;
	fin>>a>>b;
	x=a.length();
	y=b.length();
	while(x<y){
		a=a+a;
		x=x*2;
	}
	p=a.length();
	for(i=0;i<p;i++){
		if(a[i]>='A'&&a[i]<='Z'){
			a[i]=char(a[i]+32);}}
	for(i=0;i<y;i++){
		if(b[i]>='a'&&b[i]<='z'){
			if(b[i]-(a[i]-'a')>='a'){
			fout<<char(b[i]-(a[i]-'a'));}
			if(b[i]-(a[i]-'a')<'a'){
			fout<<char(b[i]+26-(a[i]-'a'));}}
		if(b[i]>='A'&&b[i]<='Z'){
			if(b[i]-(a[i]-'a')>='A'){
			fout<<char(b[i]-(a[i]-'a'));}
			if(b[i]-(a[i]-'a')<'A'){
			fout<<char(b[i]+26-(a[i]-'a'));}}}
	fin.close();
	fout.close();
	return 0;
}