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: buck, identity, culture, fawn, pester
Example Output: buck

Example Input: Category: fried food 
Words: sweet roll, seperate, fritter, dunker, dumpling
Example Output: seperate

Example Input: Category: window material 
Words: knive, acrylic, vinyl, glass, wood
Example Output:
knive