1 1
a
b b
0 0 1 b a a a b
a a
a
b
d
e
g
h
j
k
l
0 0 1 1 0 0 0 0
l l
l
k k
k
j j
j
i g
g h
h i
h
g
f d
d e
e f
c a
e
d
a b
b c
b
a