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 tumor differentiation a risk factor for lymph node metastasis in elderly patients with early gastric cancer?
Answer: Elderly patients with undifferentiated type histology early gastric cancer without other risk factors for lymph node metastasis may be candidates for endoscopic resection.
Example Output: no

Example Input: Question: Is pre-surgical cortical activation to food pictures associated with weight loss following bariatric surgery?
Answer: We found that neural activity in previously established regions associated with cognitive and behavioral self-regulation predicts weight loss following bariatric surgery. These preliminary findings highlight the role of neural circuitry in the success and maintenance of weight loss and suggest a possible future use of fMRI in screening LAGB surgery candidates.
Example Output: yes

Example Input: Question: Does preoperative chemotherapy for lung cancer increase surgical morbidity?
Answer: C+S did not significantly affect morbidity or mortality overall, based on clinical stage, postoperative stage, or extent of resection. The potential for enhanced survival in resectable NSCLC justifies continued study of C+S.
Example Output:
no