#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    int a, b;
    cin >> a >> b;

    // cout << (a & b) << endl;

    if((a & b) != a){
        cout << 0 << endl;
        return 0;
    }

    if(a == b){
        cout << 1 << endl;
        return 0;
    }

    int ans = 0;
    int cnt = __builtin_popcount(b) - __builtin_popcount(a);
    if(cnt == 0)ans = 1;
    else{
        cnt--;
        ans = 1;
        rep(i,cnt)ans *= 2;
    }
    cout << ans << endl;
    return 0;
}