#include<iostream>

using namespace std;

int main() {
	iostream::sync_with_stdio(0);
	string a,b,ans="";
	int t;
	cin>>b;
	while(b[0] != '0') {
		t = 0; ans = "";
		cin>>a;
		for(int i = 0; i < a.size(); ++i) {
			ans += (char)(a[i] + b[t] - 'A' + 1);
			if(ans[i] > 'Z') ans[i] = ans[i] -'Z' + 'A' - 1;
			//cout << (char)(a[i] + b[t] - 'A' + 1)<<endl;
			t = (t+1) % b.size();
			//cout <<t <<endl;
		}
		cin>>b;
		cout<<ans<<endl;
	}
	
	return 0;
}