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

Ex Input:
Problem: for any integer n greater than 1 , n * denotes the product of all the integers from 1 to n , inclusive . how many prime numbers are there between 6 * + 2 and 6 * + 6 , inclusive ?

Ex Output:
none


Ex Input:
Problem: . 005 / ? = . 01

Ex Output:
. 5


Ex Input:
Problem: the distance from city a to city b is 120 miles . while driving from city a to city b , cara drives at a constant speed of 30 miles per hour . dan leaves city a 120 minutes after cara . what is the minimum constant speed in miles per hour that dan must exceed in order to arrive in city b before cara ?

Ex Output:

60