In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: find √ ? / 19 = 4 ? 
Options: a ) 76 , b ) 5776 , c ) 304 , d ) 1296 , e ) none

Ex Output:
b


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 q are there between 6 * + 2 and 6 * + 6 , inclusive ? 
Options: a ) none , b ) one , c ) two , d ) three , e ) four

Ex Output:
a


Ex Input:
Problem: what is the 23 th digit to the right of the decimal point in the decimal form of 36 / 66 ? 
Options: a ) 3 , b ) 4 , c ) 8 , d ) 9 , e ) 6

Ex Output:

b