Today in Russia it's not just the 20th of september, it's Recruiter's Day. In Azerbaijan – Oil Industry Worker's Day, and in Belarus – Customs Officer's Day. But for us it's another good day to arrange the round. Welcome to Codeforces Beta Round #29 (Div. 2, Codeforces format)!
Helped with preparation of the round: Mike Mirzayanov, Dmitry Matov, Gerald Agapov and Nickolay Kuznetsov, thank them for that.
Happy Recruiter's Day,