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: Does systematic mediastinal lymphadenectomy increase postoperative immune response after major lung resections?
Answer: Systematic lymphadenectomy added to major lung resection does not increase postoperative humoral immune response in uncomplicated cases, as measured by levels of IL-6 and IL-1 ra in serum, pleural fluid, and sputum.
Output:
no