B'Given 2 integers u and v , find the shortest array such that bitwise-xor of its elements is u , and the sum of its elements is v . The only line contains 2 integers u and v (0 <= u,v <= 10^{18}) . 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. In the first sample, 3 oplus 1 = 2 and 3 + 1 = 4 . There is no valid array of smaller length. Notice that in the fourth sample the array is empty. '...