Trie: count stored words

Trie: count how many words are stored

Insert several lowercase words into a Trie and print the number of distinct words.

Key idea: in a Trie each complete word corresponds to one node marked isEnd=true; all other nodes are just prefixes on the way. So the word count equals the number of isEnd nodes, independent of total node count; inserting the same word twice still counts once.

countWords (which recursively counts isEnd nodes) is provided. You only complete insert: descend per character, create missing edges, and mark the final node isEnd=true — forget it and nothing gets counted.

Input

• Line 1: number of words n.
• Next n lines: one lowercase word (a-z) each.

Output

• One line: the number of distinct words.

Example: inserting cat car card dog do (5 distinct words) -> 5.