n n
n
n
p
a b
p
a b
p
p
a b
p
a b
p
a b
a b
p
a b
p
a b
p
p
p
p
p
b
b c b c
p
b c b c
p
a b c
b c b c
p
p
a b c
a b c
a b c
p
a b c
a b c
p
b c
a b c
a b
p
a b c
a
a b c
a b c
p
p
a b c
p
p
a b c
a b c
p
a c
b c
p
d
d a
d b
d c
p
b
b a
c b
p
b d
c d
c d
d
a b
c d
a d ad bc
T
n n n
n n k n k
n
n