#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <complex>
using namespace std;

typedef long long ll;
typedef uint64_t ull;
typedef pair<int, int> P;
typedef pair<int, double> Pid;
typedef pair<double, int> Pdi;
typedef pair<ll, int> Pl;
typedef pair<ll, ll> Pll;
typedef pair<int, pair<int, int>> PP;
typedef pair<P, int> PPi;
constexpr double PI = 3.1415926535897932;   // acos(-1)
constexpr double EPS = 1e-9;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define chadd(x, y) x = (x + y) % mod

bool check(vector<int>& v){
    int sz = v.size();
    for(int i = 0; i < sz; ++i){
        if(v[i])    return true;
    }
    return false;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    string s, t;
    cin >> s >> t;
    reverse(s.begin(), s.end());
    reverse(t.begin(), t.end());
    int ns = s.length(), nt = t.length();
    vector<int> a(ns), b(nt);
    for(int i = 0; i < ns; ++i) a[i] = s[i] - '0';
    for(int i = 0; i < nt; ++i) b[i] = t[i] - '0';
    vector<int> A;
    while(check(a)){
        A.push_back((a[0] % 2 == 0) ? 0 : 1);
        if(a[0] % 2 != 0)   --a[0];
        a[0] /= 2;
        for(int i = 1; i < ns; ++i){
            int foo = 10 * a[i];
            foo /= 2;
            a[i - 1] += foo % 10;
            a[i] = foo / 10;
        }
    }
    vector<int> B;
    while(check(b)){
        B.push_back((b[0] % 2 == 0) ? 0 : 1);
        if(b[0] % 2 != 0)   --b[0];
        b[0] /= 2;
        for(int i = 1; i < nt; ++i){
            int foo = 10 * b[i];
            foo /= 2;
            b[i - 1] += foo % 10;
            b[i] = foo / 10;
        }
    }
    int na = A.size(), nb = B.size();
    if(na > nb) swap(A, B), swap(na, nb);
    vector<int> ans(nb);
    for(int i = 0; i < na; ++i) ans[i] = A[i] ^ B[i];
    for(int i = na; i < nb; ++i)    ans[i] = B[i];
    vector<int> ans2(10000, 0);
    int digit_cnt = 1, digit_cnt2 = 1;
    vector<int> pow2(10000, 0);
    pow2[0] = 1;
    if(ans[0])  ans2[0] = 1;
    for(int i = 1; i < ans.size(); ++i){
        vector<int> hoge(10000, 0);
        for(int j = 0; j < digit_cnt; ++j){
            int foo = pow2[j] * 2;
            hoge[j] += foo % 10;
            int bar = hoge[j];
            hoge[j] = bar % 10;
            bar /= 10;
            foo /= 10;
            foo += bar;
            int add = 1;
            while(foo){
                hoge[j + add] += foo % 10;
                int bar2 = hoge[j + add];
                hoge[j + add] = bar2 % 10;
                bar2 /= 10;
                foo /= 10;
                foo += bar2;
                chmax(digit_cnt, j + add + 1);
                ++add;
            }
        }
        pow2 = hoge;
        chmax(digit_cnt2, digit_cnt);
        if(!ans[i]) continue;
        for(int j = 0; j < digit_cnt2; ++j){
            ans2[j] += pow2[j];
            int foo = ans2[j];
            ans2[j] = foo % 10;
            foo /= 10;
            int add = 1;
            while(foo){
                ans2[j + add] += foo % 10;
                int bar = ans2[j + add];
                ans2[j + add] = bar % 10;
                bar /= 10;
                foo /= 10;
                foo += bar;
                chmax(digit_cnt2, j + add + 1);
                ++add;
            }
        }
    }
    for(int i = digit_cnt2 - 1; i >= 0; --i)    cout << ans2[i];
    cout << endl;
    // reverse(s.begin(), s.end());
    // reverse(t.begin(), t.end());
    // int X = atoi(s.c_str()), Y = atoi(t.c_str());
    // cerr << X << " " << Y << endl;
    // cerr << (X ^ Y) << endl;
}