Given a set of five words, generate the word from the set that does not belong (i.e. is the least relevant) with the other words. Words are separated by commas.

Ex Input:
order office supplies, sort mail, file, program, type

Ex Output:
program


Ex Input:
happy, substance, shop, tools, content

Ex Output:
happy


Ex Input:
variety, balanced, fair, tone, light

Ex Output:

balanced