Hello everyone, The Iranian Combinatorics Olympiad is back! WITH LOTS OF CHANGES!!!

For those who are not familiar with this competition, this is an online event which is free to register and participate in. Everyone can participate in this challenge in a team of at most 3! Keep in mind that all members of a team must have the same nationality!

The contest contains two rounds and students will be challenged to solve IMO style combinatorial questions. The unique and nice thing about this contest, is that it is the first contest in the world that has an online judging system for a theoretical exam. The registration is now open!

Anyone in any grade and educational level can participate in this exam.

There will be four divisions in this contest:

1) Junior Level: Students in grade 8 or below

2) Intermediate Level: Students in grade 10 or below

3) Advanced Level: Students in grade 12 or below

4) Open Level: No age restrictions

As I mentioned above, this contest is completely free and we are relying on sponsors to support such an event! To help us grow and make this contest is bigger, the only request that we have from you guys is to:

1) Participate in this event if you are interested in solving these types of problems

2) If it is possible for you, we would be happy if you can send us a short video (to our official email), introducing yourself, your nationality and say one of the sentences mentioned below of your choice which will be used to make the closing ceremony's video.

ZENDE BAAD TARKIBIAAT (which translates to "long live Combinatorics)

ZE GAHVARE TA GOOR DANESH BEJOOY (Look forward to learn new materials from your birth until death)

TARKIBIAAT BARAYE SOLH (Combinatorics for peace)

We would like to thank you in advance for your kind support.

THE DEADLINE FOR REGISTRATION IS NOVEMBER 9th

The event will be on two days,

The first round will be held on Friday November 20th, 2026 from 14:00 to 16:00 (Iran time)

The second round will be held on Friday November 27th, 2026 from 14:00 to 19:00 (Iran time)

official website: https://ico-official.com

email: [email protected]

If you have any questions, you can ask under this blog and I will try my best to answer them as much as possible.

The first round will be a short-answer examination and the second round will be a long-answer examination

Qualification for the second round:

At most two top performing teams from each country other than Iran are included in a candidate pool based on the results of the first day. Top 30 teams in advanced division and the Top 20 teams in the open division will automatically qualify for the next round. In addition, within each division, the highest-ranked team from every country not yet represented among the Day 2 qualifiers is placed in a separate pool. The five highest-ranked teams in this pool also qualify for Day 2.

Registration instruction:

• First, each team member must independently create a personal account on this link

• Then, the team leader must visit this link and register the team by entering the names of all team members

• Finally, each team member (Except the team leader) must login to their personal account, go to their profile and accept the team leader's invitation to join the team

This new system allows us to track the individuals competing in this competition for many years (and different teams) so that we can eventually build a hall of fame for you guys.

--------------------CHANGES TO LAST YEAR && IMPORTANT INFO-------------------

1) There is one week of gap between the first round and the second round!

2) There will be no more offline division and only online division exists

3) Simple calculators are permitted, consulting reference materials or searching online is permitted only to understand terminology in a problem statement or to clarify linguistic. Using artificial intelligence tools to find ideas, perform calculations or construct proof is prohibited (for the spirit of the competition)

4) We are introducing two special awards this year which is listed below:

• The golden pigeon award dedicated to the memory of Ebadollah Mahmoudian, recognizes the team presenting the most creative solution in the proof-based examination, considering the Advanced and Open division together

• The golden die award, dedicated to the memory of Maryam Mirzakhani, may be awarded when exactly one team, across the advanced and open division combined, receives full marks for a particular proof-based problem and no other team receives full mark for that same problem. The award is conditional and may not be presented in a given year

5) Closing ceremony will be held on Friday, December 4th, 2026 with online live broadcasting!

6) The result of the previous year is mentioned in my previous blog

For more information have a look at the official telegram channel of the event.