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.

[EX Q]: Context: A farmer had 105 green tomatoes and 71 red tomatoes in his garden. If he picked 137 tomatoes 

 Question: How many tomatoes are left?
[EX A]: 39

[EX Q]: Context: After eating a hearty meal they went to see the Buckingham palace. There, Rachel learned that 100 visitors came to the Buckingham palace on the previous day. If there were 666 visitors on that day 

 Question: How many more visitors visited the Buckingham palace on that day than on the previous day?
[EX A]: 566

[EX Q]: Context: Josh had 7 marbles in his collection. He lost 8 marbles and found 10 new ones. 

 Question: How many more marbles did he find than those he lost?
[EX A]:
2