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

Ex Input:
Problem: how many positive integers less than 20 can be expressed as the sum of a positive multiple of 2 and a positive multiple of 3 ?

Ex Output:
14


Ex Input:
Problem: a man can row 6 kmph in still water . when the river is running at 3 kmph , it takes him 1 hour to row to a place and black . what is the total distance traveled by the man ?

Ex Output:
4.5


Ex Input:
Problem: the area of one square is x ^ 2 + 6 x + 9 and the area of another square is 4 x ^ 2 − 28 x + 49 . if the sum of the perimeters of both squares is 56 , what is the value of x ?

Ex Output:

6