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

Example Input: Problem: 1370 , x , 1070 , - 180 , - 6430
Example Output: 1320

Example Input: Problem: a train crosses a bridge of length 200 m in 10 seconds and a lamp post on the bridge in 5 seconds . what is the length of the train in metres ?
Example Output: 200 m

Example Input: Problem: rs . 1581 is divided among a , b and c in the ratio 10 : 15 : 6 . what is the share of b ?
Example Output:
306