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: Does in a safety net population HPV4 vaccine adherence worsen as BMI increases?
Answer: Obesity, as well as gravidity and Hispanic race, are risk factors for lack of HPV4 vaccine adherence among young females in a safety net population.

Ex Output:
yes


Ex Input:
Question: Are common genetic variants related to vitamin D status associated with esophageal squamous cell carcinoma risk in China?
Answer: Our results suggested that common genetic variants related to vitamin D levels are not associated with risk of ESCC in this Chinese population.

Ex Output:
no


Ex Input:
Question: Does n-acetylcysteine administration improve patient outcome after liver resection?
Answer: In spite of promising experimental evidence, this study was not able to demonstrate any advantage in the routine administration of peri-operative NAC in patients undergoing a liver resection.

Ex Output:

no