Hi everyone!

The fourth round of COCI will be held tomorrow, January 25th at 14:00 UTC. You can access the judging system here. If you are not familiar with the COCI contest format, we encourage you to read the announcement.

The round was prepared by fbabic, vito1036, jcelin, psruk, and me.

Feel free to discuss the problems in the comment section after the contest ends.

Hope to see you tomorrow!