v 0 0 0
v 1 0 0
v 0.5 1 0
v 0.5 -1 0
v 0.5 0 -1
v 0.5 0 1
v -0.5 0.2 0
v 1.5 0.2 0
v -0.5 -0.2 0
v 1.5 -0.2 0

f 1 2 3
f 1 2 5
f 2 1 4
f 2 1 6

f 2 6 8
f 2 8 3
f 2 4 10
f 2 10 5

f 6 1 7
f 7 1 3
f 4 1 9
f 9 1 5