Hi Codeforces!

I'm glad to introduce you to Codeforces Round 558 (Div. 2), which will take place on May/09/2019 18:05 (Moscow time).

You will have 6 problems and 2 hours to solve them. Two problems will have subtasks. Round will be rated for everyone with rating below 2100. Participants from the first division can also participate out of competition as usual.

The problems were prepared by me, ArguteOnAir, Shirone, and GreymaneSilverfang. I would like to thank cdkrot for his immense help during the round preparation, 300iq, mohammedehab2002, and Um_nik for testing them, and of course MikeMirzayanov for the Codeforces and Polygon platforms.

In the contest, you will meet Kuro, Shiro, Katie, and Selena, the four naughty but smart cats who love playing and asking questions. I hope you will find our problems interesting.

I will be in the community Discord server after the contest to discuss the problems with you. You can find the server here!

Good luck!

UPD1: Problem B and C will have 2 subtasks. The scoring distribution will be 500 — (750 + 500) — (1000 + 750) — 2250 — 2750 — 3250.

UPD2: The contest will be delayed by 15 minutes due to technical reasons. Sorry for the inconvenience :(

UPD3: Final standings!

Div. 1:

1. ainta (the only contestant to finish all problems!)

2. dreamoon_love_AA

3. hank55663

4. tfg

5. pmnox

Div. 2:

1. xht37

2. Ekoos

3. beka_asd

4. bbao69

5. OIerDb

The editorial is available here. Thank you for participating!