The task is to generate the correct answer for a given math problem.

Example Input: Problem: how many liters of a 40 % iodine solution need to be mixed with 35 liters of a 20 % iodine solution to create a 32 % iodine solution ?
Example Output: 102

Example Input: Problem: how many digits are required to number a book containing 240 pages ?
Example Output: 612

Example Input: Problem: ben left a job paying $ 75000 per year to accept a sales job paying $ 45000 per year plus 15 percent commission . if each of his sales is for $ 750 , what is the least number of sales he must make per year if he is not to lose money because of the change ?
Example Output:
267