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 ii(): return int(input())
def mi(): return map(int, input().split())
def ai(): return list(map(int, input().split()))

u,v = mi()
if u>v or u&1 != v&1:
	print(-1)
elif u==0 and v == 0:
	print(0)
else:
	x = (v-u)//2
	if x:
		if u&x!=0:
			print(3)
			print(u,x,x)
		else:
			print(2)
			print(u+x,x)
	else:
		print(1)
		print(u)