#include <bits/stdc++.h>
using namespace std;
const int MASK = (1 << 20) - 1;
int main() {
  long long s, x;
  cin >> s >> x;
  int count1 = 0, count2 = 0;
  int count3 = 0, count4 = 0;
  for (int a = 0; a < 1 << 20; ++a) {
    int b = (int)((x ^ a) & MASK);
    if (((a + b) & MASK) == (int)(s & MASK)) {
      if (a + b <= MASK) {
        ++count1;
      } else {
        ++count2;
      }
    }
    b = (int)((x >> 20) ^ a);
    if (a + b == (int)(s >> 20)) {
      ++count3;
    } else if (a + b + 1 == (int)(s >> 20)) {
      ++count4;
    }
  }
  long long result = count1 * (long long)count3 + count2 * (long long)count4;
  if (s == x) result -= 2;
  cout << result << endl;
  return 0;
}
