The problems have been prepared by me. I want to thank Codeforces team: tasks coordinator Gerald Agapov (Gerald) for invaluable contribution to the preparation of tasks and Maria Belova (Delinur), who has translated the problems. Also thank to Niyaz Nigmatullin (niyaznigmatul) for testing.
I wish you all good luck and have a good weekend!
UPD: You can see score distribution at the problems page.
UPD2: You can find editorial here.