Help in a Combinatoric problem

Revision en1, by Virtual_Contestant, 2020-05-05 20:28:20

Can anyone please explain the solution for this problem? I have looked at multiple solutions and editorial but unable to understand from them. Thanks a lot. https://codeforces.com/problemset/problem/804/B

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en1 English Virtual_Contestant 2020-05-05 20:28:20 235 Initial revision (published)