Codeforces Round #602 (Div. 2, based on Technocup 2020 Elimination Round 3) E. Arson In Berland Forest ¶þ·Ö ǰ׺ºÍ

E. Arson In Berland Forest The Berland Forest can be represented as an infinite cell plane. Every cell contains a tree. That is, contained before the