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: how many odd 3 - digit integers greater than 800 are there such that all their digits are different ? 
Options: a ) 40 , b ) 56 , c ) 72 , d ) 81 , e ) 104

Ex Output:
c


Ex Input:
Problem: the average of 13 numbers is 60 . average of the first 7 of them is 57 and that of the last 7 is 61 . find the 8 th number ? 
Options: a ) 43 , b ) 30 , c ) 35 , d ) 45 , e ) 50

Ex Output:
a


Ex Input:
Problem: there are 2 white plates , 6 green plates , 8 red plates , 4 pink plates , and 10 purple plates in the cabinet . what is the least number of plates that you have to pull out to make sure that you will have a matching pair ? ( assume that all the plates are identical except for the color ) 
Options: a ) 2 , b ) 4 , c ) 12 , d ) 7 , e ) 6

Ex Output:

e