Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

Example Input: Category: geographical property 
Words: flat, horizontal, smooshed, elevation, house
Example Output: house

Example Input: Category: animal 
Words: stingray, horse, iguana, wrestle, fish
Example Output: wrestle

Example Input: Category: bird 
Words: sandpiper, crane, hummingbird, neck, digger
Example Output:
digger