FINAL UPDATE: The contest is now over! The problems are available for upsolving in the Codeforces gym, and you can also read the editorial here. Thanks for participating!

And congratulations to the top teams (out of 1500 points):

As well as the top high-school teams:

Update: Opening Ceremony is starting at https://www.youtube.com/watch?v=dN3Gk0rUhnk !!! PLEASE JOIN US!!

Hey there! LexMACS (Lexington Mathematical Computer Science club) is proud to announce that LIT (Lexington Informatics Tournament) is back for 2026!

LIT is composed of 2 rounds: the standard round and the Capture-The-Flag ( CTF ) Cybersecurity round. The standard round is a team competitive programming contest with 10 problems and a 3-hour contest window. The CTF round will rely on contestants’ knowledge of computer security and general problem-solving skills to complete challenges and locate a "flag" for each. Some of our problem-setters and testers include C0DET1GER, CodingPokemon, CatsAreCool, Euclid73, Modulus998244353, Ninjaprime, joshadoodle, and rayxu66.

This year, the Standard Round will feature a brand new format! Inspired by guts rounds in math competitions, there will be 10 problems divided into 4 sets. You can only see Set 1 at the start, and your team can choose to “unlock” the next set, but doing so will apply a decay multiplier to any future submissions you make on the previous sets (the points you have before unlocking will remain). The specific point values are as follows:

• Set 1: 4 problems, 100 points each
• Set 2: 3 problems, 150 points each
• Set 3: 2 problems, 200 points each
• Set 4: 1 problem, 250 points (Note: just like how the last set is usually estimation problems in Guts rounds, we will reveal that this problem would be an output only constructive problem with test cases for all skill levels!)

If you unlock a new set, the multiplier is 0.8 if you’re submitting to a problem in the set immediately before the current one, 0.6 if you’re submitting to a problem two sets before, and 0.4 if you’re submitting to a problem three sets before.

Example Scenario: Your team solves 3 out of 4 problems in set 1, yielding 300 points. If your team decides to unlock set 2, the score of any future submissions to any problem in set 1 will be multiplied by 0.8, meaning your score on set 1 is capped at 380.

See https://lit.lhsmathcs.org/rules/ for more specific information on the format.

Participants may create teams of up to 3 members! You can choose to start the standard round at any time during our 4-day contest window (July 31, 11 am ET to August 4, 11 am ET). You can also solve challenges from the CTF round at any time between August 1, 11 am ET and August 3, 11 am ET. For more info on LIT logistics, visit https://lit.lhsmathcs.org/.

Top 5 teams from both the standard and CTF rounds will receive cash prizes! We also have cash prizes specific to both college/post-high school and middle school students, along with game night cash prizes! Regardless of your skill level, we promise that the contest will provide something exciting and refreshing!

For more info on LIT prizes, see the "Prizes" section on our homepage.

For more LIT 2026 details, join our Discord server or visit our website !!!!!

:D HOPE TO SEE YOU GUYS THIS YEAR!!!

Sincerely, LexMACS Organizers <3