#include <bits/stdc++.h>
using namespace std;
long long int s, x, dp[100][10][10][10], ar[100][100];
long long int solve(int c, int d, int a, int b) {
  if (c > 50) {
    if (a && b && !d) return 1;
    return 0;
  }
  long long int &ret = dp[c][d][a][b];
  if (ret != -1) return ret;
  ret = 0;
  if (ar[1][c] == 0 && d % 2 == ar[0][c])
    ret += solve(c + 1, d / 2, a | 0, b | 0);
  if (ar[1][c] == 1 && (1 + d) % 2 == ar[0][c])
    ret += solve(c + 1, (d + 1) / 2, a | 1, b | 0);
  if (ar[1][c] == 1 && (1 + d) % 2 == ar[0][c])
    ret += solve(c + 1, (d + 1) / 2, a | 0, b | 1);
  if (ar[1][c] == 0 && (2 + d) % 2 == ar[0][c])
    ret += solve(c + 1, (d + 2) / 2, a | 1, b | 1);
  return ret;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> s >> x;
  memset(dp, -1, sizeof(dp));
  for (int i = 0; i <= 51; i++) {
    if (s & (1ll << i)) ar[0][i] = 1;
    if (x & (1ll << i)) ar[1][i] = 1;
  }
  cout << solve(0, 0, 0, 0);
}
