번호	제목
13228	The REAL Manhattan distance
13229	Selection Sum
13230	Bits equalizer
13231	Lucky Tickets
13232	Domain clusters
13233	Celtic Symmetry
13234	George Boole
13235	팰린드롬
13236	Collatz Conjecture
13237	Binary tree
13238	Bitcoin investment
13239	Combinations
13240	Chessboard
13241	최소공배수
13242	Harps and Tails
13243	Non-decreasing subsegment
13244	Tree
13245	Sum of digits
13246	행렬 제곱의 합
13247	토끼의 이동