Problem: Given 2 integers u and v, find the shortest array such that [bitwise-xor](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of its elements is u, and the sum of its elements is v.

Input

The only line contains 2 integers u and v (0 ≤ u,v ≤ 10^{18}).

Output

If there's no array that satisfies the condition, print "-1". Otherwise:

The first line should contain one integer, n, representing the length of the desired array. The next line should contain n positive integers, the array itself. If there are multiple possible answers, print any.

Examples

Input


2 4


Output


2
3 1

Input


1 3


Output


3
1 1 1

Input


8 5


Output


-1

Input


0 0


Output


0

Note

In the first sample, 3⊕ 1 = 2 and 3 + 1 = 4. There is no valid array of smaller length.

Notice that in the fourth sample the array is empty.

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
std::mt19937 rng(
    (int)std::chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1000000007;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long u, v;
  cin >> u >> v;
  if (u > v) {
    cout << -1 << '\n';
    return 0;
  }
  if (u == 0 and v == 0) {
    cout << 0 << '\n';
    return 0;
  }
  if (u == v) {
    cout << 1 << '\n';
    cout << u << '\n';
    return 0;
  }
  if ((v - u) % 2LL == 0) {
    long long a = (u + v) / 2LL;
    long long b = v - a;
    if ((a ^ b) == u) {
      cout << 2 << '\n';
      cout << a << " " << b << '\n';
    } else {
      cout << 3 << '\n';
      cout << u << " " << ((v - u) / 2LL) << " " << ((v - u) / 2LL) << '\n';
    }
  } else {
    cout << -1 << '\n';
  }
  return 0;
}