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

Input: Consider 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 ?

Output: none


Input: Consider Input: Problem: a reduction of 20 % in the price of oil enables a house wife to obtain 4 kgs more for rs . 600 , what is the reduced price for kg ?

Output: 30


Input: Consider Input: Problem: a person ' s present age is two - fifth of the age of his mother . after 4 years , he will be one - half of the age of his mother . how old is the mother at present ?


Output: c ) 20