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: grasshopper, fly, walk, bus, eagle
Example Output: bus

Example Input: current, history, wave, jetstream, whirlpool
Example Output: history

Example Input: neck, chord, output cord, fret, concerned
Example Output:
concerned