Given the task definition, example input & output, solve the new input case.
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: Context: Sam is 6 feet tall and Alex is 5 feet tall 

 Question: By how many feet is Sam taller than Alex? 
Output: 1
 Sam's height - Alex's height = 6-5 = 1

New input case for you: Context: Jerry had 7 action figures on a shelf in his room. Later he added some more action figures to the shelf and removed 10 of the old ones. If there are 8 action figures on his shelf now 

 Question: How many action figures did he add to the shelf?
Output:
11