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 chronic cerebrospinal venous insufficiency associated with chronic venous disorders : A case-control study?
Answer: We found no association of CCSVI with the presence of CVD or family history of varicose veins.
Example Output: no

Example Input: Question: Does creatine supplementation affect kidney function in an animal model with pre-existing renal failure?
Answer: Creatine supplementation at a dosage of 2% w/w for 4 weeks does not impair kidney function in animals with pre-existing renal failure or in control animals.
Example Output: no

Example Input: Question: Is gene and Protein Expression of Chemokine ( C-C-Motif ) Ligand 19 Upregulated in Unstable Carotid Atherosclerotic Plaques?
Answer: CCL19 is significantly overexpressed in patients with unstable carotid atherosclerotic plaques and may be a possible novel biomarker for identifying high-risk patients in whom more urgent intervention may be indicated.
Example Output:
yes