#include<iostream> #include<string> #include<vector> #include<algorithm> #include<bitset> #include<set> #include<map> #include<stack> #include<queue> #include<deque> #include<list> #include<iomanip> #include<cmath> #include<cstring> #include<functional> #include<cstdio> #include<cstdlib> #include<unordered_map> #include<unordered_set> using namespace std; #define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++) #define rep(i, n) repr(i, 0, n) #define INF 2e9 #define MOD 1000000007 //#define MOD 998244353 #define LINF (long long)4e18 #define jck 3.141592 const double EPS = 1e-10; using ll = long long; using Pi = pair<int,int>; using Pl = pair<ll,ll>; int main(){ int A,B; cin >> A >> B; if(A == B){ cout << 1 << endl; return 0; } vector<int> a,b; while(A > 0){ a.push_back(A%2); A /= 2; } while(a.size() < 40){ a.push_back(0); } while(B > 0){ b.push_back(B%2); B /= 2; } while(b.size() < 40){ b.push_back(0); } ll ans = 1; rep(i,40){ if(a[i] == 0 && b[i] == 1) ans *= 2; else if(a[i] == 1 && b[i] == 0) ans *= 0; } cout << ans/2 << endl; }