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.

Example Input: there are 396 students going to a trivia competition . if each school van can hold 9 students how many vans will they need ?
Example Output: 44

Example Input: a chef had 77 cherries . if he used 60 of them to make a pie how many cherries would he still have ?
Example Output: 17

Example Input: you have 7 balloons and your friend has 5 balloons . what 's the difference of the number of your balloons and your friend 's balloons ?
Example Output:
2