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.

Ex Input:
Category: employment activity 
Words: fire, hire, ground, pay, retire

Ex Output:
ground


Ex Input:
Category: boats 
Words: head, hull, knockout, deck, dock

Ex Output:
knockout


Ex Input:
Category: secretary duty 
Words: support, file, program, order office supplies, reception

Ex Output:

program