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.

[Q]: Context: Ed had 12 more marbles than Doug. Ed lost 20 of his marbles at the playground. If Ed had 17 marbles 

 Question: How many marbles does Doug have now?
[A]: 5


[Q]: Context: Julia played tag with 8 kids on monday, 11 kids on tuesday and 9 kids on wednesday. 

 Question: How many more kids did she play with on tuesday than on wednesday?
[A]: 2


[Q]: Context: A waiter had 14 customers. 5 customers left. 

 Question: How many customers does he still have?
[A]:
9