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: type of rigidity 
Words: tough, taut, rough, amalgamated, firm

Ex Output:
amalgamated


Ex Input:
Category: moral characteristic 
Words: frank, stern, bun, concise, precise

Ex Output:
bun


Ex Input:
Category: consumer product 
Words: content, activity, file, ecstatic, tools

Ex Output:

ecstatic