You will be given a definition of a task first, then some input of the task.
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.

Question: Is sex an independent risk factor for survival in differentiated thyroid cancer?
Answer: Male sex does not portray an independent survival risk in differentiated thyroid cancer when survival is compared by disease stage. Men present at a later age with more advanced disease, which may explain their poorer survival seen in some studies.
Output:
no