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:
XOR, SUM = map(int, input().split())
if XOR > SUM or XOR % 2 != SUM % 2:
	print(-1)
elif SUM == 0:
	print(0)
elif XOR == SUM:
	print(1)
	print(SUM)
else:
	a = (SUM - XOR) // 2
	if (a ^ XOR) == a + XOR:
		print(2)
		print(a ^ XOR, a)
	else:
		print(3)
		print(a, a, XOR)