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: Does exacerbation of headache during dihydroergotamine for chronic migraine alter outcome?
Answer: After controlling for nausea and other factors, headache exacerbation with DHE infusions is not an independent predictor of poor headache outcome and clinicians should not interpret its presence as a reason to stop treatment. The focus of management should be on controlling nausea as it is the most important modifiable factor in achieving a good headache outcome with an inpatient course of IV DHE for chronic migraine.
Example Output: no

Example Input: Question: Is the risk of uterine rupture increased with single- compared with double-layer closure : a Swedish cohort study?
Answer: There was no significant difference in the rate of uterine rupture when single-layer closure was compared with double -layer closure of the uterus.
Example Output: no

Example Input: Question: Do low-abundance HIV drug-resistant viral variants in treatment-experienced persons correlate with historical antiretroviral use?
Answer: Low-abundance HIV drug-resistant mutations in antiretroviral-experienced subjects at time of virologic failure can increase a subject's overall burden of resistance, yet commonly go unrecognized by conventional genotyping. The majority of unrecognized resistant mutations correlate with historical antiretroviral use. Ultra-deep sequencing can provide important historical resistance information for clinicians when planning subsequent antiretroviral regimens for highly treatment-experienced patients, particularly when their prior treatment histories and longitudinal genotypes are not available.
Example Output:
yes