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.

Example Input: Jerry had 7 action figures , but needed 16 total for a complete collection . If each one costs $ 8 , how much money would he need to finish his collection ?
Example Output: 72

Example Input: A new building needed 11 windows . The builder had already installed 4 of them . If it takes 8 hours to install each window , how long will it take him to install the rest ?
Example Output: 56

Example Input: A worksheet had 3 problems on it . If a teacher had 15 worksheets to grade and had already graded 7 of them , how many more problems does she have to grade ?
Example Output:
24