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

Example Input: Problem: find the value of x : 2 x 4 .
Example Output: - 2,2

Example Input: Problem: country c imposes a two - tiered tax on imported cars : the first tier imposes a tax of 12 % of the car ' s price up to a certain price level . if the car ' s price is higher than the first tier ' s level , the tax on the portion of the price that exceeds this value is 8 % . if ron imported a $ 14,000 imported car and ended up paying $ 1640 in taxes , what is the first tier ' s price level ?
Example Output: $ 1300

Example Input: Problem: a certain telephone company offers two plans , a and b . under plan a , the company charges a total of $ 0.60 for the first 9 minutes of each call and $ 0.06 per minute thereafter . under plan b , the company charges $ 0.08 per minute of each call . what is the duration of a call , in minutes , for which the company charges the same amount under plan a and under plan b ?
Example Output:
3