#include"bits/stdc++.h"
using namespace std;
#define REP(k,m,n) for(int (k)=(m);(k)<(n);(k)++)
#define rep(i,n) REP((i),0,(n))
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using tp3 = tuple<int, int, int>;
using Mat = vector<vector<ll>>;
constexpr int INF = 1 << 28;
constexpr ll INFL = 1ll << 60;
constexpr int dh[4] = { 0,1,0,-1 };
constexpr int dw[4] = { -1,0,1,0 };
bool isin(const int H, const int W, const int h, const int w) {
    return 0 <= h && h < H && 0 <= w && w < W;
}
template<typename T>
T minch(T& l, T r) {
    return l = min(l, r);
}
template<typename T>
T maxch(T& l, T r) {
    return l = max(l, r);
}
template<typename T>
void output(const T& val) {
    cout << val << endl;
}
template<typename T>
void output(const vector<T>& vec, const bool newline = false) {
    for (const T& val : vec)cout << val << (newline ? '\n' : ' '); cout << endl;
}
template<typename T>
void output(const vector<vector<T>>& mat) {
    for (const auto& row : mat)output(row);
}
// ============ template finished ============

int main()
{
    string A, B;
    cin >> A >> B;
    reverse(A.begin(), A.end());
    reverse(B.begin(), B.end());
    while (A.size() < B.size())A += "0";
    while (A.size() > B.size())B += "0";

    string res;
    rep(i, A.size())res += A[i] == B[i] ? "0" : "1";
    reverse(res.begin(), res.end());
    output(res);
    return 0;
}