Today, June 12, when Russia celebrates Day of itself, Euro 2012 second round starts and I_love_natalia has a birthday, we present you Codeforces Round #124.
Contest was prepared by team Samara SAU Teddy Bears (craus, dalex, Hohol) and I_love_natalia. Also thanks to Alex_KPR and Codeforces team (Gerald, Delinur, MikeMirzayanov). We think that contest is very easy, and your task will be prove of refute this assertion :)
Scoring system is dynamic (Learn more about dynamic problem scoring).
Authors think that problems are sorted by difficulty in non-descending order.
Accepted solutions and successful hacks to you!
UPD. Contest is over, congratulations to the winners!
Div-1 (full results):
Div-2 (full results):
UPD 2. Tutorial is available.