Instructions: 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: Is routine drainage necessary after laparoscopic gastric bypass?
Answer: Routine abdominal drainage is not necessary after a successful laparoscopic gastric bypass for morbidly obese patients. Drainage omission may contribute to a quicker recovery without additional surgical complications.
Output:
no