P1666 Prefix Words

A set of words is safe if and only if no word is a prefix of another word; this ensures that the data is not easily misunderstood. Now you have a word set $S$, and you need to count how many of its subsets are safe. Note that the empty set is always safe.

The first line contains an integer $n$, the size of the set. Then $n$ lines follow. Each line contains a string consisting of \verb!a!\cdots\verb!z!.

The number of safe subsets.

### Constraints and Conventions - For $30\%$ of the testdata, it holds that $1 \le n \le 10$. - For $100\%$ of the testdata, it holds that $1 \le n \le 50$, string length $\le 50$, and no two strings are exactly the same. Translated by ChatGPT 5