#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;
#define ep emplace_back
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);++i)
constexpr int mod=1000000007;
constexpr int mod1=998244353;
vector<int> dx={0,1,0,-1},dy={-1,0,1,0};
bool inside(int y,int x,int h,int w){
	if(y<h && y>=0 && x<w && x>=0) return true;
	return false;
}





int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	ll a,b;cin >> a >> b;
	bitset<32> A(a), B(b);
	ll ans = 1;
	bool flg = false;
	for(int i = 0; i < 32; i++){
		if(A[i]){
			if(!B[i]){
				ans = 0;
			}
		}
		else{
			if(B[i]){
				if(flg) ans *= 2;
				else flg = true;
			}
		}
	}
	cout << ans << endl;
}