Ciao, Codeforces! We're glad to invite you to take part in Codeforces Round 975 (Div. 1) and Codeforces Round 975 (Div. 2), which will start on 27.09.2024 16:35 (Московское время). You will be given 6 problems and 2 hours and 30 minutes to solve them in both divisions. Some problems will be divided into subtasks.

UPD: the time has been changed to 27.09.2024 16:35 (Московское время), which is different from the time announced before. Please note the unusual starting time.

This round is based on Italian Olympiad in Informatics (OII) 2024.

The problems were authored by lorenzoferrari, wksni and me.

We would like to thank

• KAN for his nutella coordination;
• Alexdat2000 for Russian translation;
• bortoz, collodel, dp_1, franfill, franv, harniver, jamesbamber, Kaey, veluca93, Virv for helping with both this contest and the onsite contest preparation;
• bortoz for pictures in the statements;
• Flamire for VIP testing;
• Um_nik, EgorUlin, konsteros, Mihail_Podyachih, bugrova, Ludissey, Nonoze, Sofapuden, Temmie, jeroenodb for testing;
• MikeMirzayanov for creating Codeforces and Polygon.

Score distribution:

• Div. 1: $$$500 - 750 - 750 - 1500 - (2250 + 750) - (1500 + 1500 + 1500)$$$
• Div. 2: $$$500 - 1000 - 1750 - 2000 - 2000 - 3000$$$

We hope you'll like the problemset!

Update 1: the editorial is here.

Update 2: congratulations to the winners!