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