Xor Equation

#include <bits/stdc++.h>
using namespace std;
#define PB push_back
#define ZERO (1e-10)
#define INF (1<<29)
#define CL(A,I) (memset(A,I,sizeof(A)))
#define DEB printf("DEB!\n");
#define D(X) cout<<"  "<<#X": "<<X<<endl;
#define EQ(A,B) (A+ZERO>B&&A-ZERO<B)
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
#define IN(n) int n;scanf("%d",&n);
#define FOR(i, m, n) for (int i(m); i < n; i++)
#define REP(i, n) FOR(i, 0, n)
#define F(n) REP(i, n)
#define FF(n) REP(j, n)
#define FT(m, n) FOR(k, m, n)
#define aa first
#define bb second
void ga(int N,int *A){F(N)scanf("%d",A+i);}
#define K(A,I) ((A>>I)&1)
#define MX (59)//REMEMBER
ll S,X,dp[MX][2][2][2];
ll dyn(int u,bool c,bool f,bool g){
    if(u==MX)return f&&g&&!c;
    ll &v(dp[u][c][f][g]);
    if(~v)return v;
    v=0;
    F(2)FF(2)if(((i^j)==K(X,u))&&((i+j+c)&1)==K(S,u))
        v+=dyn(u+1,(i+j+c)>=2,f|i,g|j);
    return v;
}
int main(void){
    scanf("%lld%lld",&S,&X);
    CL(dp,-1);
    printf("%lld\n",dyn(0,0,0,0));
    return 0;
}