#ifndef INCLUDED_MAIN
#define INCLUDED_MAIN

#include __FILE__

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

    if((a&(~b))!=0) {
        cout<<0<<nl;
        return 0;
    }
    ll pp=max(a,b);
    rep(dig,10) {
        if((1ll<<dig)>pp) {
            numdig=dig;
            break;
        }
    }

    ll ans=1;
    rep(i,numdig) {
        bool ai=((a>>i)&1),bi=((b>>i)&1);
        if(ai&&bi) ans*=2;
    }
    cout<<ans<<nl;
    return 0;
}

/////// library zone ///////
#else
#include <bits/stdc++.h>
#include <atcoder/segtree>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define srep(i,l,r) for(ll i=l;i<=r;i++)
using ll = long long;
using ld = long double;
const ll mod=998244353;
#define vout(v) for(auto i :v) cout<<i<<" ";
#define INF 9223300000000000000ll
#define Winf 5e12
#define nl "\n"
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define vl vector<ll>
#define vc vector<char>


ll op(ll a,ll b) {return a+b;}
ll e() {return 0ll;}



template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}

void no() { cout<<"No"<<nl;}
void yes() { cout<<"Yes"<<nl;}
void yn(bool a) {
    cout<<(a ? "Yes":"No")<<nl;
}

ll sum(vector<ll>& a) {
    ll ans=0;
    for(auto i:a) ans+=i;
    return ans;
}



ll modpow(ll fl, ll po, ll mode) {  // mode: 0=modなし, 1=modあり
    ll ret=1;
    if (mode) {
        while (po>0) {
            if (po&1) ret=(ret*fl)%mod;
            fl=(fl*fl)%mod;
            po>>=1;
        }
    } else {
        while (po>0) {
            if(po&1) ret*=fl;
            fl*=fl;
            po>>=1;
        }
    }
    return ret;
}

#endif