번호	제목
21821	Acowdemia II
21822	Acowdemia III
21823	Swap Swap Sort
21824	Weird Numeral System
21825	Through Another Maze Darkly
21826	Travelling Merchant
21827	Bread First Search
21828	Loop Town
21829	Secret
21830	Vote-Value Disparity 2
21831	Vote-Value Disparity 3
21832	Vote-Value Disparity 4
21833	Vote-Value Disparity 5
21834	Contact Tracing
21835	Coronavirus Testing
21836	Quarantine Math
21837	Border Restrictions
21838	One-way Sidewalks
21839	Mutant Vaccine
21840	Sorting Device