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.

Example Input: pay, praise, fire, inferno, let go
Example Output: inferno

Example Input: unflappalbe, refreshing, funny, cool, confident
Example Output: refreshing

Example Input: specialty, books, ecstatic, file, content
Example Output:
ecstatic