Instructions: 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.
Input: Question: Does sertraline alter the beta-adrenergic blocking activity of atenolol in healthy male volunteers?
Answer: The results of this study demonstrate that sertraline does not alter the beta-blocking activity of atenolol.
Output:
no