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: Sam is 6 feet tall and Alex is 5 feet tall

Question: By how many feet is Sam taller than Alex?
Example output: 1
Example explanation: Sam's height - Alex's height = 6-5 = 1
Q: Context: Kelly has 20 nintendo games and 70 sony games.

Question: How many nintendo games does she need to give away so that she will have 12 nintendo games left?
A:
8