Gunwoo is currently at house and wants to move to house . He can use a teleportation device to move between houses. This device has buttons, and an integer is written on the -th button. Pressing -th button moves him from house to house . Here, denotes the bitwise OR operation. Gunwoo can use this device at most times. Determine whether he can move from house to house , and if so, find the sequence of buttons he needs to press.
Input
The first line contains integers separated by a space. The second line contains integers separated by a space.
Output
If Gunwoo can go from house to house , print , the number of times the device will be used on the first line. Then, print the indices of the buttons to press in order on the second line, separated by a space.
If he cannot go to house , print -1.
Here, must be an integer between and , inclusive. If there are multiple valid answers, you may print any of them.
Constraints
Subtasks
Samples
Initially, he is at house . Pressing the 1st button moves him to house since . Pressing the 2nd button moves him to house since .
The bit that is already turned on at the initial position is not turned on in . Since the bitwise OR operation cannot turn off this bit again, it is impossible to move to house .
He is at house from the beginning, so he does not need to press any buttons.