#include <bits/stdc++.h>
using namespace std;

int main() {
  ios::sync_with_stdio(false);

  int A, B;
  cin >> A >> B;

  auto solve = [&]() {
    vector<vector<int>> dp(32, vector<int>(2));
    dp[0][0] = 1;
    for (int i = 0; i + 1 < 32; ++i) {
      int a = A >> 30 - i & 1;
      int b = B >> 30 - i & 1;
      if (a && !b) return 0;
      for (int l = 0; l < 2; ++l) {
        if (a == b) dp[i + 1][l] += dp[i][l];
        if (!a && b) {
          if (l) {
            dp[i + 1][l] += 2 * dp[i][l];
          } else {
            dp[i + 1][1] += dp[i][l];
          }
        }
      }
    }
    return dp[31][0] + dp[31][1];
  };

  cout << solve() << endl;
  
  return 0;
}