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 a, b, c, d;
void zxy() {
  cin >> a >> b;
  if (a == 0 && b == 0) {
    puts("0");
    return;
  }
  if (a == b) {
    cout << 1 << endl << a << endl;
    return;
  }
  if (a > b) {
    puts("-1");
    return;
  }
  c = b - a;
  d = c / 2;
  if (c % 2 != 0) {
    puts("-1");
    return;
  }
  if ((d ^ a) == (d + a)) {
    cout << 2 << endl << (a ^ d) << ' ' << d << endl;
    return;
  } else {
    cout << 3 << endl << a << ' ' << d << ' ' << d << endl;
    return;
  }
}
int main() { zxy(); }