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: window material 
Words: plastic, woodwork, glass, bowl, spyhole
Example Output: bowl

Example Input: Category: secretary duty 
Words: correspondence, schedule, answer calls, keys, file
Example Output: keys

Example Input: Category: baby animals 
Words: culture, doe, colt, bambi, fawn
Example Output:
culture