Everybody knows that jiry_2 = Syloviaely.
There are different accounts on the website, and some of them competed in the recent contests. However, Mike suspects that there are lots of alternative accounts.
There are axioms believed by everyone that nobody can use two different in one contest simultaneously and each account can be owned by only one person. So different accounts without overlapping contest participation can be owned by the same person.
Mike wants to know the minimum possible number of different people behind these accounts.

The first line contains two integers.
Each of the following  lines contains an integer 
first, followed by  distinct integers  indicating the accounts participating the contest.
Some accounts may not participate in any contests.

Output one integer - the answer.

5 3
2 1 2
3 2 3 4
4 4 5 1 2

4