번호	제목
20696	Tree Beauty
20697	Robust Defense
20698	Police Stations
20699	Almost Balanced Tree
20700	Brain-teaser
20701	Color the Tree
20702	Down We Dig
20703	Easy Measurements
20704	Find a Square
20705	Geometrical Combinatorics
20706	Hit the Hay
20707	Interactive Knockout
20708	Jumping Cat
20709	Kate's 2021 Celebration
20710	Lookup Performance
20711	Miser
20712	New Flat
20713	Optimum Server Location
20714	Colored Squares
20715	Island Archipelago