9 	/* Number of nodes */
a	/* Node labels */
b
c
d
e
f
g
h
i
a b 4.0  /* Edge a->b has cost 4.0 */
b c 8.0 
c d 7.0
d e 9.0
d f 14.0
e f 10.0
c f 4.0
g f 2.0
c i 2.0
g i 6.0
i h 7.0
g h 1.0
b h 11.0
a h 8.0