870A - Search for Pretty Integers Idea, preparation, editorial komendart
870B - Maximum of Maximums of Minimums Idea DPR-pavlin, preparation, editorial mHuman
870C - Maximum splitting Idea, preparation, editorial komendart
870D - Something with XOR Queries Idea, preparation, editorial mHuman
870E - Points, Lines and Ready-made Titles Idea, preparation, editorial komendart
870F - Paths Idea, preparation, editorial komendart
871E - Restore the Tree Idea MikeMirzayanov, preparation fcspartakm, editorial mHuman
Also many thanks to coordinator KAN, testers ifsmirnov, vintage_Vlad_Makeev, AlexFetisov and any other people who participates in preparation of contest.
Code (C++) 31365874
Code (Python) 31365844
Code 31366254
Code 31365909
Code 31366223
Code 31365959
Code 31366002
Code 31368704