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

int main(void) {
  int A, B;
  cin >> A >> B;
  long long ans = 0;
  int digits = min((int)log2(A), (int)log2(B));
  for (int i = 0; i < digits; i++) {
    if (!(A & (1 << i)) && (B & (1 << i))) {
      ans++;
    }
  }
  cout << 2 * (ans - 1) << endl;
  return 0;
}