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: mode of transportation 
Words: bus, fly, jog, beetle, drive

Ex Output:
beetle


Ex Input:
Category: employment activity 
Words: ban, fire, empower, sack, ground

Ex Output:
ground


Ex Input:
Category: window material 
Words: cup, vinyl, panel, glass, coating

Ex Output:

cup