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 unexplained elevated maternal serum alpha-fetoprotein predictive of adverse perinatal outcome in an indigent urban population?
Answer: Elevated maternal serum alpha-fetoprotein levels offer little if any additional predictive value for adverse perinatal outcome in populations already at high risk for such outcomes on the basis of obstetric or socioeconomic criteria.
Example Output: no

Example Input: Question: Do skin stretching for primary closure of acute burn wounds?
Answer: Skin Stretch for primary closure of acute burn wounds is a suitable technique and can be considered for specific circumscript full-thickness burn wounds. However, future research should be performed to provide additional scientific evidence.
Example Output: yes

Example Input: Question: Is altered perineal microbiome associated with vulvovaginitis and urinary tract infection in preadolescent girls?
Answer: Vulvovaginitis may cause UTIs by altering the perineal biome such that there is increased colonization of uropathogens.
Example Output:
yes