"Should have rather rushed Bombsite B. On a serious note, is this really what 7th Grade Russians study? That is really impressive, no wonder Russians are such good coders.""Russian kids are seriously genious.""When you realize that this was actually a Div. 1 contest""Was this div 2? this was Div 1 ! Even more difficult , Div 0 maybe""Don't worry, its my 21st contest, and even I couldn't solve a single problem.""this contest is for grade 5 to 8,OMG i can only imagine the level of Russian kids.""How the hell those russian kids are solving? I am feeling like idiot""this contest is for grade 5 to 8,OMG i can only imagine level of Russian kids"Отсюда https://codeforces.com/blog/entry/80214