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

Example Input: Context: Paul had 71 books. After selling some in a garage sale he bought 38 new ones. If he has 116 books now 

 Question: How many more books did he buy than he sold?
Example Output: 45

Example Input: Context: A waiter had 8 customers. After some left he still had 5 customers. Then he got 99 new customers 

 Question: How many customers left?
Example Output: 3

Example Input: Context: Ed had 19 more marbles than Doug. Ed lost some of his marbles at the playground. Now Ed has 8 more marbles than doug. 

 Question: How many marbles did Ed lose?
Example Output:
11