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:
'''
	@judge CodeForces
	@id 1325D
	@name Ehab the Xorcist
	@contest Codeforces Round #628

	@tag Math, Greedy, Binary Operations
'''
from sys import stdin

for line in stdin:
	u, v = map(int, line.split())
	if u > v or (v - u) % 2 == 1:
		print('-1')
	elif u == v:
		if v == 0:
			print('0')
		else:
			print('1')
			print(u)
	else:
		t = (v - u) // 2
		if (u & t) == 0:
			print('2')
			print(f'{u + t} {t}')
		else:
			print('3')
			print(f'{u} {t} {t}')