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: Is prooxidant-anti-oxidant balance associated with extent of coronary artery disease?
Answer: In conclusion, we found higher levels of oxidative stress in CAD+ patients compared to healthy subjects. The oxidation level was not related to measures of the extent of CAD such as number of stenosed vessels.

Ex Output:
no


Ex Input:
Question: Is nitric oxide-dependent renal vasodilatation altered in rat with rHuEpo-induced hypertension?
Answer: The analysis of our results seems to indicate that the endogenous NO system activity was enhanced in rHuEpo-induced hypertension in rats with normal renal function and a resistance to NO was not developed in renal circulation. Further studies seem to be necessary to better clarify the exact mechanisms underlying the development of rHuEpo-induced hypertension.

Ex Output:
no


Ex Input:
Question: Is playground Safety Associated With Playground , Park , and Neighborhood Characteristics?
Answer: Park safety levels need to be improved to reduce the risk of physical injuries. Future studies examining cause-effect associations between environmental features and playground safety are warranted.

Ex Output:

yes