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:
x, s = map(int, input().split())
if x > s:
    print(-1)
    exit(0)
if x == s == 0:
    print(0)
    exit(0)
if x == s:
    print(1)
    print(x)
    exit(0)

if x == 0 and s % 2 == 1:
    print(-1)
    exit(0)
elif x == 0:
    print(2)
    print(s // 2, s // 2)
    exit(0)
if (s + x) % 2 == 1:
    print(-1)
    exit(0)
lol = (s - x) // 2
if lol ^ (s - lol) == x:
    print(2)
    print(lol, s - lol)
    exit(0)
print(3)
print(lol, lol, x)