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

Ex Input:
Roger is at the library helping put away books . There are 14 book to put away total but a librarian takes 2 of them and leaves Roger with the rest . If he can fit 3 books on a shelf , how many shelves will he need ?

Ex Output:
4

Ex Input:
Keith spent $ 136.01 on speakers , $ 139.38 on a CD player , and $ 112.46 on new tires . He wanted 3 CD 's for $ 6.16 , but did n't buy them . In total , how much did he spend ?

Ex Output:
387.85

Ex Input:
Kaleb had 10 video games but 8 of them were n't working . If he wanted to sell the working games for $ 6 each , how much money could he earn ?

Ex Output:
12