Hint to solve problem

#1

Please provide some hint to solve this problem.

#2

a) a cb number is need not to be a prime number.

b) u should first mark all 1 lenght cb numbr and then 2 and then 3 so on. becuase we want to maximize it.

image

Reference Code

#3

I hope I’ve cleared your doubt. I ask you to please rate your experience here
Your feedback is very important. It helps us improve our platform and hence provide you
the learning experience you deserve.

On the off chance, you still have some questions or not find the answers satisfactory, you may reopen
the doubt.