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 extracorporeal shockwave lithotripsy in patients with distal ureteral calculi influence the prostate specific antigen value?
Answer: Treatment of distal ureteral calculi with SWL does not affect the serum PSA concentration.
Output:
no