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.

Example Input: Question: Is routine preoperative lymphoscintigraphy necessary prior to sentinel node biopsy for breast cancer?
Answer: Preoperative lymphoscintigraphy adds little additional information to intraoperative lymphatic mapping, and its routine use is not justified.
Example Output: no

Example Input: Question: Is cigarette smoking associated with a reduction in the risk of incident gout : results from the Framingham Heart Study original cohort?
Answer: Cigarette smoking is associated with lower incidence of gout and this is not explained by differences in the prevalence of risk factors. The mechanistic underpinnings of this epidemiological finding merits further study.
Example Output: yes

Example Input: Question: Does sildenafil citrate affect cardiac contractility in human or dog heart?
Answer: Sildenafil is unlikely to directly produce inotropic effects on cardiac muscle in patients being treated for erectile dysfunction.
Example Output:
no