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: 5357 x 51 = ? 
Options: a ) 273232 , b ) 273243 , c ) 273247 , d ) 273250 , e ) 273207

Ex Output:
e


Ex Input:
Problem: the mean of 50 observations was 36 . it was found later that an observation 48 was wrongly taken as 23 . the corrected new mean is : 
Options: a ) 36.5 , b ) 35 , c ) 34 , d ) 33 , e ) 32.5

Ex Output:
a


Ex Input:
Problem: on the richter scale , which measures the total amount of energy released during an earthquake , a reading of x - 1 indicates one - tenth the released energy as is indicated by a reading of x . on that scale , the frequency corresponding to a reading of 7 is how many times as great as the frequency corresponding to a reading of 5 ? 
Options: a ) 10 ^ 2 , b ) 10 ^ 3 , c ) 10 ^ 4 , d ) 10 ^ 5 , e ) 10 ^ 6

Ex Output:

a