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: Are perioperative nonselective non-steroidal anti-inflammatory drugs associated with anastomotic leakage after colorectal surgery?
Answer: There does not appear to be a significant association between perioperative ketorolac use and anastomotic leakage after colorectal surgery. However, further prospective studies are needed to confirm our findings before definitive guidelines on NSAID use perioperatively can be recommended.

Ex Output:
no


Ex Input:
Question: Does dual tasking during postural stepping responses increase falls but not freezing in people with Parkinson 's disease?
Answer: For people with PD and FoG, forward falls may not always be caused by FoG, particularly under attention-distracting conditions.

Ex Output:
yes


Ex Input:
Question: Is morphine the only analgesic in palliative care : literature review?
Answer: Nurses need to be aware of treatment options that may benefit patients with difficult pain problems. Although positive experiences have been documented when using alternatives to morphine, more research must be conducted to allow practitioners to add more pharmaceutical alternatives to their pain management armouries.

Ex Output:

no