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 solve(x,s):
    # s = x + 2*a
    a = (s-x)//2
    aa,bb = 0,0
    for i in range(0,64):
        ai = (1<<i) & a
        xi = (1<<i) & x
        if ai == 0 and xi == 0:
            pass
        elif ai > 0  and xi == 0:
            aa = (1<<i) | aa
            bb = (1<<i) | bb
        elif ai == 0 and xi > 0:
            aa = (1<<i) | aa
        else:
            return [x,a,a]
    return [aa,bb]
x,s = map(int,input().split())
if x == s == 0:
    print(0)
elif x == s:
    print(1)
    print(x)
elif x > s or (s-x)%2:
    print(-1)
else:
    ans = solve(x,s)
    print(len(ans))
    print(*ans)