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: current, dastards, prompt, course, timely
Example Output: course

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

Example Input: firstrate, fine, comfortable, well, ok
Example Output:
firstrate