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.

Example Input: Category: military rank 
Words: regular, major, general, soldier, cadet
Example Output: regular

Example Input: Category: mode of transportation 
Words: beetle, fly, soar, bus, car
Example Output: beetle

Example Input: Category: accomodation 
Words: squashed, cabin, flat, smooth, round
Example Output:
smooth