Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.

Ex Input:
Question: Do clinical and radiological courses differ between fluid-attenuated inversion recovery-positive and negative patients with stroke after thrombolysis?
Answer: Visibility of lesions on FLAIR in areas of diffusion restriction was not predictive of the response to thrombolysis.

Ex Output:
no


Ex Input:
Question: Does the usage of overtube have a favorable effect on endoscopic submucosal dissection?
Answer: We conclude that using an overtube during an upper gastrointestinal ESD decreases the need for suction, favors the speed of dissection, and eases the comfort of the procedure.

Ex Output:
yes


Ex Input:
Question: Does bile duct size predict success of portoenterostomy for biliary atresia?
Answer: Children presenting early in infancy (<3 months) with biliary atresia should undergo a portoenterostomy regardless of the size of the bile ducts at the time of exploration.

Ex Output:

no