Happy Holidays to the Codeforces community! I have a new contest to share with you all.

Abakoda 2021 was an initiative by NOI.PH (the Philippines' olympiad) to run a series of beginner-friendly weekly contests, which ultimately culminated in a long contest. Contestants were given a little under 10 days to solve 15 problems. We have decided to share these problems with the general Codeforces community. We hope you find them useful and interesting!

The contest link is here: https://codeforces.me/gym/103496 EDIT: Problems are now live! Enjoy :D

The problems will be available starting 6:00 pm this Dec 27 (UTC+8), and will remain "live" in the Gym until 11:59 pm on Jan 5 (again, UTC+8). Most of the problems in the contest are standard, since the contest is targeted at beginners, but I think even experienced participants will find some of the problems interesting. As long-format, I think this contest would be educational for people up to Green or Cyan level. More experienced contestants could even treat these 15 problems as an easy ICPC set. I would even guess that an Orange could solo 93% to 100% of the problems within a 5 hour period.

Regardless, I think the problems should be relatively interesting, and I'm quite proud of my work, so please check it out :D It will be fun! I also guaranteed that all these problems are comfortably solvable using Python (though you might need to submit to PyPy or still use fast I/O for some of them). Furthermore, each problem contains custom art that I commissioned from a close friend of mine, so make sure to read all the problems to see them all!

The problem stories feature Alice, Bob, and Cindy, the same characters from my Dagitab 2021 long contest last year. Except now I'm not a broke college student, so I was able to afford art for all three of them this time!

Thank you to the wonderful testers of these problems:

• spacewalker
• Something_hacker
• verngutz

Thanks also to kevinsogo whose KompGen library was invaluable in creating the test data for all these problems. And of course, thanks to MikeMirzayanov for Codeforces and the Polygon platform.

We hope you enjoy the Abakoda 2021 Long Contest!