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;
int main() {
  long long a, b, x, y, z;
  cin >> a >> b;
  if (a > b)
    cout << -1 << endl;
  else if (a == b) {
    if (a == 0)
      cout << 0 << endl;
    else
      cout << 1 << endl << a << endl;
  } else {
    y = b - a;
    if (y & 1)
      cout << -1 << endl;
    else {
      x = y / 2;
      z = x ^ a;
      if (z == x + a)
        cout << 2 << endl << a + x << " " << x << endl;
      else
        cout << 3 << endl << a << " " << x << " " << x << endl;
    }
  }
}