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: elements 
Words: fire, earth, water, blaze, recruit
Example Output: recruit

Example Input: Category: mode of transportation 
Words: spider, fly, drive, train, soar
Example Output: spider

Example Input: Category: elements 
Words: ground, fire, scold, blaze, earth
Example Output:
scold