You are given a math word problem and you are supposed to apply a single mathematical operator like addition, subtraction, multiplication, or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Input: Consider Input: will went to the state fair and rode the ferris wheel 13 times . if he rode it 7 times during the day how many times did he ride it at night ?

Output: 6

Input: Consider Input: the kids from oakwood elementary school are visiting a bird zoo for their field trip . to get to the bird zoo from the school the kids have to ride some buses . if there are 7 buses and each bus has 3 adult supervisors to guide the children how many supervisors are there in total ?

Output: 21

Input: Consider Input: there are 38 books on the shelf . marta put 10 more books on the shelf . how many books are on the shelf now ?
Output: 48