# Book Pile

## 题目描述

There is a pile of $N$ books on the table. Two types of operations are performed over this pile:

• a book is added to the top of the pile,
• top $K$ books are rotated. If there are less than $K$ books on the table, the whole pile is rotated.

First operation is denoted as $ADD(S)$ where $S$ is the name of the book, and the second operations is denoted as $ROTATE$.
The maximum number of books is no more than $40000$. All book names are non-empty sequences of no more than $3$ capital Latin letters. The names of the books can be non-unique.

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