This is not a gotcha question. It's a smoke test: something that should be really easy to get right.
This is like building a calculator that can't get 1+1 correct, and then complaining nobody would ever need a calculator to calculate 1+1 so therefore it's an unfair question.
This is like building a calculator that can't get 1+1 correct, and then complaining nobody would ever need a calculator to calculate 1+1 so therefore it's an unfair question.