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: bird 
Words: ostrich, digger, sandpiper, crane, goose
Example Output: digger

Example Input: Category: shady activities 
Words: invent, smuggled, smear, fudge, pie
Example Output: pie

Example Input: Category: computers 
Words: ram, file, prepare, keys, format
Example Output:
prepare