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: police punishment 
Words: fine, prime, firstrate, comfortable, ticket
Example Output: comfortable

Example Input: Category: window material 
Words: glass, coating, panel, spatula, lead
Example Output: spatula

Example Input: Category: secretary duty 
Words: prepare, file, organize, errands, folder
Example Output:
folder