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: emotional display 
Words: follow, doe, suppressed, culture, fawn
Example Output: doe

Example Input: Category: consumer product 
Words: shop, tools, happy, service, content
Example Output: happy

Example Input: Category: measurement unit 
Words: finger, mile, kilometer, yard, foot
Example Output:
finger