#include <iostream>

using namespace std;

int main()
{
    string s1, s2;
    cin >> s1 >> s2;
    for (unsigned int i = 0; i < s1.length(); i++)
    {
        if (s1[i] == s2[i])
        {
            cout << 0;
        }
        else
        {
            cout << 1;
        }
    }
    return 0;
}