In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.

[EX Q]: How many times has alec baldwin hosted saturday night live?
[EX A]: 17

[EX Q]: Where does the ulna articulate with the humerus?
[EX A]: semilunar notch

[EX Q]: The main difference between isotopes of the same element?
[EX A]:
neutron number, and consequently in nucleon number