In this task, you are given a context tweet, a question and corresponding answer of given question. Your task is to classify given passage into two categories: (1) "yes" if the given context is useful in answering the question, and (2) "no" if the given context is not useful.
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Question: Context: Hey everybody, thanks for your concern. We're all safe & doing well in the Russian segment. Follow @Nasa for updates on @Space_Station today Sam Cristoforetti (@AstroSamantha) January 14, 2015 Question: who balked on conditions? Answer: munchak

Answer: no

Question: Context: Katy Perry rocking the Wii safety strap during the halftime show. #SuperBowl Funny Or Die (@funnyordie) February 2, 2015 Question: who was wearing a safety strap? Answer: katy perry

Answer: yes

Question: Context: Challenge over! Orange team has reactivated the power and sent the power turning! #rtncyberf2f CyberSecChallengeUK (@Cyberchallenge) February 21, 2015 Question: what challenge happened recently? Answer: cyber challenge uk

Answer:
yes