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

Example Input: Problem: meena wrote all the numbers from 1 to 29,999 inclusive . how many digits did she write in total ?
Example Output: 138,889

Example Input: Problem: find the cost of fencing around a circular field of diameter 16 m at the rate of rs . 3 a meter ?
Example Output: 150.84

Example Input: Problem: the area of a circular field is 17.56 hectares . find the cost of fencing it at the rate of rs . 4 per metre approximately
Example Output:
5943