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

Example Input: A group of science students went on a field trip . They took 6 vans and 8 buses . There were 6 people in each van and 18 people in each bus . How many people went on the field trip ?
Example Output: 180

Example Input: A teacher had 34 worksheets to grade . If she graded 7 , but then another 36 were turned in , how many worksheets would she have to grade ?
Example Output: 63

Example Input: The Silvergrove Public Library used a grant to purchase 2647 books . Now the library has a total of 8582 books . How many books did the library have before the grant ?
Example Output:
5935