If 'COMPUTER' is decoded as '3,15,13,16,21,20,5,18'. Then 'MATHEMATICS' is decoded as:
13,1,20,8,5,1,31,20,9,3,1,9
13,1,20,8,5,13,1,20,9,3,19
1,3,1,20,8,5,1,3,2,9,13,19
13,1,20,8,15,13,20,9,13,19