¡Buenas, Codeforces!
We are super excited to announce Codeforces Round 1127 (Div. 1, Div. 2), which will start on Oct/11/2026 21:35 (Moscow time) Note the starting time is 4 hours later than the usual. The contest will be split into 2 divisions where you will be given 6 problems and 2 hours to solve them. At least one problem will be interactive so we recommend reading the guide on interactive problems
Div. 1 score distribution: $$$500 - 1000 - 1250 - 2000 - 2250 - 3500$$$
Div. 2 score distribution: $$$500 - 1250 - 1250 - 1750 - 2000 - 3000$$$
This round is based on the Mexican Olympiad in Informatics (OMI) 2026. All problems were written and prepared by our team of pupils, aka writers, namely jampm, Francisco_Martin, Teto, SopaconK, Remgagagali727, Marckess, and efishel. We hope you enjoy it and maybe learn something about Mexican culture along the way.
The team would like to thank:
cry for their considerate coordination (and ample basement).
All these pupils, aka testers, for their support and great feedback (we love you): SpyrosAliv, AksLolCoding, turska, JoenPoenMan, kevinyang, miniyahirpro, AmShZ, pyoro, Blagoj, br1g, Juanchoki, prvocislo, osvarp, ecnerwala, Argentum47, Keshi, prins, racsosabe, danielrmzkuhn1, 0xor1, temporary1, nik_exists, nifeshe, Edu175, CSQ31, tourist.
Alexdat2000 for translating statements.
ocarima et familia for their many years supporting the Mexican Olympiad in Informatics and pushing us to grow.
MikeMirzayanov & KAN. You know why :)
Writers + ozy1220: 
As a tester, I really hope that the competitors at the top of the standings don't have the same rating as the authors
The authors color in the post dont match their rating :sob:
As a writer you're right. I wish to be pupil.
As a writer, I miss being a pupil
As a writer I also wish to be pupil.
as a pupilo, i wish to be a pupil
As a writer I wish you enjoy the problems and get a positive delta :)
As a tester, I was definitely not tricked into testing by Remgagagali727.
As a tester, I love efishel
Good time for the chinese students.
Div.2 B and C gonna be crazy since they have the same points :)