I'd like to thank keyvankhademi, AlexFetisov, winger, Belonogov, cyand1317 and demon1999, AnPelec for testing, KAN for coordinating the round and MikeMirzayanov for the great Codeforces and Polygon platforms.
The main characters of the round are Stranger Things characters.
The scoring distribution will be announced soon.
Good luck and have fun.
UPD0: The round is over, we hope you enjoyed it. Editorial will be posted soon.
UPD1: System testing is over, congratulations to the winners.
Div.1 winners are:
And Div.2 winners are:
The editorial will be posted in a bit.