You are given a math word problem and you are supposed to apply multiplication or division mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Ex Input:
At lunch a waiter had 7 customers and 5 of them did n't leave a tip . If he got $ 3 each from the ones who did tip , how much money did he earn ?

Ex Output:
6

Ex Input:
Kaleb was collecting cans for recycling . On Saturday he filled 5 bags up and on Sunday he filled 5 more bags . If each bag had 4 cans in it , how many cans did he pick up total ?

Ex Output:
40

Ex Input:
Adam bought 9 packages of cat food and 7 packages of dog food . Each package of cat food contained 10 cans , and each package of dog food contained 5 cans . How many more cans of cat food than dog food did Adam buy ?

Ex Output:
55