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.
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Question: heron, davit, egret, derrick, crane

Answer: davit


Question: fair, color, unprejudiced, fine, decent

Answer: color


Question: ethical, tropical, unflappalbe, cool, optimist

Answer:
tropical