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: fly, glide, flutter, eagle, train
Example Output: eagle

Example Input: protein, chunky, big boned, fat, capacitance
Example Output: protein

Example Input: forward, down, up, emotional state, descending
Example Output:
emotional state