See also Nos. 256, 257, and 258 in _A. in M._
[Illustration
A
Y
YOY
YOBOY
YOY
Y
B
L
LEL
LEVEL
LEL
L
C
N
NON
NOOON
NOONOON
NOOON
NON
N
D
L
LEL
LEVEL
LEVEVEL
LEVELEVEL
LEVEVEL
LEVEL
LEL
L ]
The Canterbury Puzzles, and Other Curious Problems · 第 185 / 286 题