Two rounds
How to participate
Joining IRCHO takes a few minutes. Round 1 is free and open to students worldwide.
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1
Register
Create your free entry. We email you the Round 1 problem set on the opening day.
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2
Round 1 — solve & submit
Work on the problems independently for up to one month. Submit your solutions as a PDF before the deadline.
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3
Round 2 — Final
Qualifying participants are invited to the Final — a monitored online session with advanced problems. All finalists receive a physical certificate signed by our Scientific Advisor.
Eligibility
- Currently enrolled in a high school or university programme.
- No national selection required — register directly via this website.
- A valid email address and willingness to follow the rules of fair play.
What you will need
- Basic stationery, a way to scan your work, and a reliable internet connection.
- A scanner or smartphone capable of producing a clear PDF (up to 10 MB).
- For the Final: a working webcam and a quiet room.
Technical requirements
- A modern browser (Chrome, Firefox, Safari, Edge — current versions).
- Stable internet connection sufficient to upload a 10 MB PDF.
- For the Final: a videoconferencing client (Zoom / Meet / Whereby — link provided).