Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.

Ex Input:
dave had 16 apps on his phone . after deleting some he had 8 left . how many apps did he delete ?

Ex Output:
8

Ex Input:
jasmine also bought some chips for her friends in which she got for a discount of $ 17 . if the chips originally cost $ 35 how much did she actually spend on chips ?

Ex Output:
18

Ex Input:
while playing a game edward had 15 lives . he lost 8 lives on a hard level . how many lives does he have left ?

Ex Output:
7