#include <iostream>
#include <cstring>
using namespace std;


string XOR(string data, string key) {
    // Dividend is data
    // Divisor is the primary key, i.e. the key
    string result = "";
    int len = data.length();

    // Performing XOR operation
    for (int i=0; i<len; i++) {
        if (data[i] == key[i]) {
            result = result + "0";
        }
        else {
            result = result + "1";
        }
    }
    return result;
}

int main() {
	string data, key;

	cout<<endl<<"Enter data:\t";
	getline(cin, data);
	cout<<"Enter primary key:\t";
	getline(cin, key);

	cout<<XOR(data, key);

	return 0;

}