#include <iostream>
#include <string>

using namespace std;

int code(char c) {
	if (c <= '9') return c - '0';
	return 10 + c - 'a';
}

void solve() {
	string s;
	cin >> s;
	string d;
	cin >> d;
	for (int i = 0; i < d.length(); i += 2) {
		char c = code(d[i]) * 16;
		c += code(d[i +  1]);
		c ^= s[(i / 2) % s.length()];
		cout << c;
	}
}

int main() {
	solve();
	return 0;
}