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:
def main():
    u,v = map(int,input().split())
    if u > v:
        print(-1)
        return

    if u == v:
        if u == 0:
            print(0)
            return
        print(1)
        print(u)
        return
    
    diff = v-u
    if diff%2 == 0:
        arr = [u,diff//2,diff//2]
        a = diff//2
        b = v-a
        if a&b == diff//2:
            arr = [a,b]
    else:
        print(-1)
        return

    print(len(arr))
    for i in arr:
        print(i,end = ' ')

main()