Hi!

Thanks to all of you participates, who made this contest possible. And thanks to Lewin and Arterm, also to the great coordinator, Nikolay KAN Kalinin, zemen, WHITE2302, and for sure MikeMirzayanov.

I'll publish test data and code solutions soon.

Hints

Div.2 A: Take a look at notes section.

Div.2 B: Create a circle with these points.

Div.1 B: Fix the gcd.

Div.1 C: Tag: Grundy number.

Details

Div.1 C

I want to thank my grand teacher Mojtaba moji FayazBakhsh here. Who was my teacher not only for coding but also a teacher for my life. Thanks Mojtaba! Thanks to you and all of other good teachers in the world.

Solutions

Thanks to Lewin, the writer of this tutorial.

Thanks to WHITE2302, the writer of this tutorial. I translated this tutorial to English.

I'll add editorial of 850E soon.

Thanks to Lewin, the writer of this tutorial.

I’d like to finish the editorial with the below poem by Hatef Esfahani:

Translation: What can lover (Farhad) do with the power of love? He has no choice but to hurt himself by ax because he feels jealousy to Khosrow. [More information about Khosrow and Shirin story].(https://en.wikipedia.org/wiki/Khosrow_and_Shirin).

Good luck and see you soon ;)