CF1105E.Helping Hiasat

Hiasat registered a new account in NeckoForces and when his friends found out about that, each one of them asked to use his name as Hiasat's handle.

Luckily for Hiasat, he can change his handle in some points in time. Also he knows the exact moments friends will visit his profile page. Formally, you are given a sequence of events of two types:

• $1$ — Hiasat can change his handle.
• $2$ $s$ — friend $s$ visits Hiasat's profile.

The friend $s$ will be happy, if each time he visits Hiasat's profile his handle would be $s$.

Hiasat asks you to help him, find the maximum possible number of happy friends he can get.

希亚萨特在 NeckoForces 上注册了一个新账号，当他的朋友们得知此事后，每个人都要求将自己的名字作为希亚萨特的用户名（handle）。

幸运的是，希亚萨特可以在某些特定时刻更改自己的用户名。此外，他还确切地知道每位朋友访问他个人主页的时间点。形式化地，你将获得一个由两类事件组成的序列：

• $1$ — 希亚萨特可以更改他的用户名；
• $2$ $s$ — 朋友 $s$ 访问希亚萨特的个人主页。

朋友 $s$ 将会感到开心，当且仅当他每次访问希亚萨特的个人主页时，希亚萨特的用户名恰好是 $s$。

希亚萨特请你帮助他，找出他最多能让多少位朋友感到开心。

The first line contains two integers $n$ and $m$ ($1 \le n \le 10^5, 1 \le m \le 40$) — the number of events and the number of friends.

Then $n$ lines follow, each denoting an event of one of two types:

• $1$ — Hiasat can change his handle.
• $2$ $s$ — friend $s$ ($1 \le |s| \le 40$) visits Hiasat's profile.

It's guaranteed, that each friend's name consists only of lowercase Latin letters.

It's guaranteed, that the first event is always of the first type and each friend will visit Hiasat's profile at least once.

第一行包含两个整数 $n$ 和 $m$（$1 \le n \le 10^5$，$1 \le m \le 40$）—— 分别表示事件总数和朋友总数。

接下来是 $n$ 行，每行描述一个事件，事件类型有两种：

• $1$ — Hiasat 可以更改他的用户名。
• $2$ $s$ — 朋友 $s$（$1 \le |s| \le 40$）访问了 Hiasat 的个人主页。

保证每个朋友的名字仅由小写拉丁字母组成。

保证第一个事件一定是第一种类型，且每位朋友至少会访问一次 Hiasat 的个人主页。

Print a single integer — the maximum number of happy friends.

输出一个整数——快乐朋友的最大数量。

In the first example, the best way is to change the handle to the "motarack" in the first event and to the "light" in the fourth event. This way, "motarack" and "light" will be happy, but "mike" will not.

In the second example, you can choose either "alice", "bob" or "tanyaromanova" and only that friend will be happy.

在第一个例子中，最优方案是在第一次事件中将昵称更改为“motarack”，在第四次事件中更改为“light”。这样，“motarack”和“light”会感到开心，但“mike”不会。

在第二个例子中，你可以选择“alice”、“bob”或“tanyaromanova”中的任意一个，仅该朋友会感到开心。