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

Example Input: Problem: i had rs . 10000 with me . out of this , money i lent some money to a for 2 years at 15 % simple interest . i lent the remaining money to b for an equal number of years at 18 % simple interest . after 2 years , i found that a had given me rs . 360 more as interest as compared to ( b ) the amount of money which i had lent to b must have been
Example Output: 4000

Example Input: Problem: if the average ( arithmetic mean ) of a and b is 45 and the average of b and c is 80 , what is the value of c − a ?
Example Output: 60

Example Input: Problem: a windmill is taking advantage of strong air currents in order to produce electrical energy . on a typical day the wind speed is around 20 mph and in that speed the windmill produces 400 kw / h ( kilowatts per hour ) . on a stormy day a windmill produces 20 % more energy . how much kw / h can 3 windmills produce in two hours on a stormy day ?
Example Output:
2880 .