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: physical property 
Words: fat, angular momentum, ugly, capacitance, fiber
Example Output: fiber

Example Input: Category: bird 
Words: goose, hoist, neck, swallow, crane
Example Output: hoist

Example Input: Category: mode of transportation 
Words: car, drive, bus, fly, beetle
Example Output:
beetle