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 school-based physical activity compromise children 's academic performance?
Answer: The AS! BC model is an attractive and feasible intervention to increase physical activity for students while maintaining levels of academic performance.
Example Output: no

Example Input: Question: Is childhood maltreatment associated with depression but not with hypochondriasis in later life?
Answer: The findings suggest a robust association of childhood maltreatment with depression but not with hypochondriasis. This result does not support etiological models of hypochondriasis which rely on childhood maltreatment as a risk factor for the development of this disorder.
Example Output: yes

Example Input: Question: Is cephalic index a useful sonographic marker for trisomy 21 and trisomy 18?
Answer: In this retrospective study, CI was not found to be statistically different between the study and control groups. Although a trend towards significance was seen with T21, this difference is not clinically useful. There may be interethnic differences in the CI between fetuses. CI is not useful for aneuploidy screening by ultrasound.
Example Output:
no