11 21

a b c e f g h i j s t 

s a 3 
s b 2 
s c 3

a b 2 
a e 4 
a f 3 

b f 3 

c g 3 

e f 3 
e h 2 
e i 2 

f i 3 
f g 2 
f j 1 

g j 3 
g b 4 

h t 1 

i h 1
i t 1 
i j 4 

j t 3 


s t