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: shady activities 
Words: wrongful, fudge, unwarranted, fix, cake
Example Output: cake

Example Input: Category: secretary duty 
Words: answer calls, image, organize, file, correspondence
Example Output: image

Example Input: Category: bird 
Words: parrot, goose, crane, swallow, excavator
Example Output:
excavator