I'm surprised there's no blog post to this... just so nobody misses it:
Round 3 of Croatian Open Competition in Informatics takes place at this time today, and lasts 3 hours.
You can log in to the contest site at evaluator.hsin.hr, or register an account there if you don't have one already. Make sure to select the right contest from the list when logging in — it's not HONI, but COCI.
Everything related to the contest should be posted here in a few weeks' time (except the solutions, it seems).
Feel free to discuss the problems here after the contest is over.