Try the Chinese NOI contest type!

IMPORTANT: WHEN YOU REGISTER THIS CONTEST, IT WILL LET YOU FILL IN A VALUE, WHICH IS THE INVITATION CODE, PLEASE ENTER yc92.

This is NOT a contest made by officials of LuoGu, so the contese does NOT provide English statements. Thank you for your understanding. You CAN use AI for translation. According to the Cninese NOI rules, the problems will be judged AFTER THE CNTEST ENDS, it will end at 2026-09-30 21:00(UTC+8). We will give all the AIs extra 10 points to mark them.