Definition: 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.
Input: Question: Does recursive partitioning analysis ( RPA ) class predict survival in patients with four or more brain metastases?
Answer: Patients with four or more brain metastases seem to represent a group with unfavorable prognosis where remission of brain metastases or administration of more than 30 Gy were not associated with increased survival. The number of patients in RPA class I was too small to draw final conclusions. However, there was absolutely no survival difference between patients in class II (median survival 3.6 months) and III (median 4.2 months).
Output:
no