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: secretary duty 
Words: correspondence, schedule, answer calls, keys, file

Ex Output:
keys


Ex Input:
Category: secretary duty 
Words: fax, program, file, make coffee, answer

Ex Output:
program


Ex Input:
Category: mode of transportation 
Words: fly, glide, flutter, eagle, train

Ex Output:

eagle