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

Ex Input:
Problem: the smallest value of n , for which n + 2 is not a prime number , is

Ex Output:
2,4


Ex Input:
Problem: working together , wayne and his son can shovel the entire driveway in three hours . if wayne can shovel six times as fast as his son can , how many hours would it take for his son to shovel the entire driveway on his own ?

Ex Output:
7


Ex Input:
Problem: if the remainder is 11 when positive integer n is divided by 18 , what is the remainder when n is divided by 9 ?

Ex Output:

2