번호	제목
21882	Coins on a tree
21883	Game of Wizards
21884	Boolean Expression
21885	New Puzzle
21886	Countdown
21887	Railroad
21888	Math Candies
21889	K-th order statistic
21890	File names
21891	Neatness
21892	Tax Collection
21893	Road Building
21894	The Expert
21895	Rock-Paper-Scissors for three
21896	Life in Innopolis
21897	Barrels
21898	Wedding cake
21899	Magical hourglass store
21900	String Game
21901	Bitwise Formula