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 PYTHON3):

Solution:
import sys

input = sys.stdin.readline


def main():
    U, V = [int(x) for x in input().split()]

    if U > V:
        print(-1)
        return

    if V == 0:
        print(0)
        return

    if U == V:
        print(1)
        print(U)
        return

    if abs(U - V) % 2 != 0:
        print(-1)
        return

    if ((V - U) // 2) & U == 0:
        print(2)
        print((V - U) // 2, U + (V - U) // 2)
    else:
        print(3)
        print((V - U) // 2, (V - U) // 2, U)


if __name__ == '__main__':
    main()