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;
long long int a, b, res;
int main() {
  ios_base::sync_with_stdio(false);
  cin >> a >> b;
  if (a == b && a == 0)
    cout << 0;
  else if (a == b)
    cout << 1 << "\n" << a;
  else if (a > b)
    cout << -1;
  else if ((b - a) % 2 == 1)
    cout << -1;
  else {
    res = (b - a) / 2;
    if ((a ^ res) == a + res) {
      cout << 2 << "\n";
      cout << (a + res) << " " << res;
    } else {
      cout << 3 << "\n";
      cout << a << " " << res << " " << res;
    }
  }
}