Dr. Henri is teaching a class of
young students. He knows that
of them are friends, but they have recently been divided by a controversial topic: does pineapple belong on pizza? For that reason, even if two children are friends, unless they agree on the controversial topic, they will not associate with each other and their friendship is broken.
To encourage friendships, Dr. Henri asks each of his
students to organize pairwise meetups among their friends. For example, if he asks a child with
friends to organize gatherings, the child could organize friend
to meet friend
, but won't have anybody to pair friend
with.
Dr. Henri can subtly change the opinion of the children. He wants to find some way to organize the opinions of the children such that the maximum number of children can pair up their friends perfectly.
Constraints


No student will be friends with themselves, nor will any friendship be listed multiple times.
Subtask 1 [5%]

Subtask 2 [45%]

Subtask 3 [50%]
No additional constraints.
Input Specification
The first line contains
integers
and
, the number of children and the number of friendships, respectively.
The next
lines each contain
integers
and
, indicating that child
and
are friends.
Output Specification
On the first line, output
, the maximum number of children that can pair up their friends perfectly.
On the next line, output
integers, the opinions of the
children. Each integer should be either
, indicating that the
child prefers pineapple on pizza, or
indicating that the
child does not prefer pineapple on pizza.
If there are multiple configurations of opinions achieving
, you may output any of them.
Note: your output must follow the standard convention of not having any leading or trailing whitespace, and it must end with a new line.
Sample Input
Copy
4 6
1 2
1 3
1 4
2 3
2 4
3 4
Sample Output
Copy
4
1 1 1 2
Explanation
Children
,
, and
each have
friends after being divided by the controversy. As such, they can pair each of their friends up perfectly.
For child number
, they can pair up all of their
remaining friends perfectly.
Comments
Just like real life 😔