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: Is routine preoperative lymphoscintigraphy necessary prior to sentinel node biopsy for breast cancer?
Answer: Preoperative lymphoscintigraphy adds little additional information to intraoperative lymphatic mapping, and its routine use is not justified.
Example Output: no

Example Input: Question: Are wedding rings a significant source of bacterial contamination following surgical scrubbing?
Answer: This preliminary study would suggest that a traditional band wedding ring is not a source of a bacterial load following a standard surgical scrub procedure and, as such, there is no requirement for their removal pre-operatively.
Example Output: no

Example Input: Question: Does choice of non-inferiority ( NI ) margins protect against degradation of treatment effects on an average -- an observational study of registered and published NI trials?
Answer: Only two fifths of the current NI trials had a likelihood of degradation lower than 50%, suggesting that, in majority of the NI trials, there is no sufficient protection against degradation on an average. We suggest a third hurdle for the choice of NI margins, thus contributing a sufficient degree of protection.
Example Output:
no