How Many Unique Words?

The poet brags about a huge vocabulary — count how many DIFFERENT words the poem actually uses. 📜

You get the poem as a list of words. Print how many distinct words appear, counting repeats only once. (The slow way: loops and a list, no shortcuts.)

Example:

Input: words = ["the", "cat", "and", "the", "hat"] Output: 4

Building a seen-list one word at a time, "the" repeats but "cat", "and", and "hat" are all new — 4 distinct words.