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: deck, tko, rudder, level, corner
Example Output: rudder

Example Input: fat, ugly, sugar, salt, protein
Example Output: ugly

Example Input: flap, fly, bird, swim, fish
Example Output:
flap