b
b
b
f
e
b
f
a
b
b
f
b
a
b
b
b
b
f
b
b
f
f
f
b
b
b
g
f
d
e
f
d
e
b
a
a
b
b
a
a
e
e
f
e
g
f
e
f
f
a
b
d
b
f
f
a
b
b
f
f
b
b
f
d
f
b
d
f
b
b
b
f
f
f
b
f
f
d
b
a