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

Example Input: Problem: if a - b = 6 and a 2 + b 2 = 50 , find the value of ab .
Example Output: a ) 7

Example Input: Problem: how many integers n are prime numbers in the range 200 < n < 220 ?
Example Output: 1

Example Input: Problem: a is half good a work man as b and together they finish a job in 14 days . in how many days working alone b finish the job ?
Example Output:
21