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

Example Input: Problem: how many diagonals does a polygon with 13 sides have , if one of its vertices does not connect to any diagonal ?
Example Output: 54

Example Input: Problem: a teacher grades students ’ tests by subtracting twice the number of incorrect responses from the number of correct responses . if student a answers each of the 100 questions on her test and receives a score of 76 , how many questions did student a answer correctly ?
Example Output: 92

Example Input: Problem: allay ' s internet provider offers unlimited traffic which costs $ 0.5 per day charged off at 12 a . m . the service is discontinued when client ' s debt exceeds $ 5 . if today in the morning allay makes a payment of $ 7 , for how many days , including today , will she be connected to the internet without any additional payments , given her initial balance was $ 0 ?
Example Output:
25