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:
a,b=list(map(int,input().split()))
if a==b and a==0:
    print(0)
elif a==b:
    print(1)
    print(a)
else:
    if a>b:
        print(-1)
    else:
        if (b-a)%2==0:
            c=(b-a)//2
            if c^a==c+a:
                print(2)
                print(c+a,c)
            else:
                print(3)
                print(c,c,a)
        else:
            print(-1)