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

Example Input: Problem: maxwell leaves his home and walks toward brad ' s house at the same time that brad leaves his home and runs toward maxwell ' s house . if the distance between their homes is 72 kilometers , maxwell ' s walking speed is 6 km / h , and brad ' s running speed is 12 km / h . what is the distance traveled by maxwell when they meet in the middle ?
Example Output: 24

Example Input: Problem: what is the sum of the multiples of 4 between 63 and 151 inclusive ?
Example Output: 233

Example Input: Problem: a is twice as good a workman as b and they took 6 days together to do the work b alone can do it in .
Example Output:
18 days