Detailed Instructions: You are given a math word problem and you are supposed to apply an addition mathematical operator on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
See one example below:
Problem: Context: 21 children were riding on the bus. At the bus stop 5 children got off the bus while some more got on the bus. Then there were 16 children altogether on the bus. 

 Question: How many children got on the bus at the bus stop?
Solution: 0
Explanation: Number of children who got on -> 21 - 5 + x = 16 , x = 0, hence no one got onto the bus

Problem: Context: Josh had some marbles in his collection. He lost 21 marbles. If he has 12 marbles now 

 Question: How many marbles did he have in his collection?
Solution:
33