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: construction 
Words: hoist, crane, excavator, egret, derrick
Example Output: egret

Example Input: Category: employment activity 
Words: scold, water, fire, praise, replace
Example Output: water

Example Input: Category: personal characteristic 
Words: confident, cool, relaxed, popular, refreshing
Example Output:
refreshing