That right. It is all my thinking about this problem also

Yes pi it seem the key of the problem. I think use pi and greedy to tackle this problem still okay for this problem

Thank you so much for your help

Thanks guy. With your help i can understand it , One more time thank you very much

First thank for your help so i can solve with N<= 1e6 but when i try to think with O(sqrt(n)) have no idea . Can you tell me more about it. Thank you very muchh

Can anyone tell me how to solve D :(!

Thanks for your help. I can solve this problem <3