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

Ex Input:
Problem: a hall 36 m long and 15 m broad is to be paved with stones , each measuring 8 dm by 5 dm . the number of stones required is : 
Options: a ) 180 , b ) 1800 , c ) 18 , d ) 18000 , e ) 1350

Ex Output:
e


Ex Input:
Problem: if a truck is traveling at a constant rate of 54 kilometers per hour , how many seconds will it take the truck to travel a distance of 600 meters ? ( 1 kilometer = 1000 meters ) 
Options: a ) 18 , b ) 24 , c ) 30 , d ) 36 , e ) 40

Ex Output:
e


Ex Input:
Problem: the amount of time that three people worked on a special project was in the ratio of 4 to 3 to 5 . if the project took 120 hours , how many more hours did the hardest working person work than the person who worked the least ? 
Options: a ) 25 hours , b ) 30 hours , c ) 20 hours , d ) 26 hours , e ) 32 hours

Ex Output:

c