#include<iostream>
#include<vector>

using namespace std;

int main() {
	int a,b;cin>>a>>b;
	int count = 0;
	bool isok = true;
	for(int i=0;i<30;++i){
		if((1<<i & a) && !(1<<i & b)){
			isok = false;
		}
		if((1<<i & a) && (1<<i & b)){
			count++;
		}
	}
	int ans = 1<<count;
	if(!isok)ans = 0;
	cout << ans << endl;
}