What is the fence made of?
The fence is made of wood.
    src        edge_attr  dst
0     0   to the left of    2
1     0   to the left of    1
2     1  to the right of    7
3     1  to the right of    5
4     1  to the right of    3
5     1  to the right of    0
6     2  to the right of    5
7     2  to the right of    0
8     2  to the right of    7
9     3         touching    2
10    3          petting    2
11    3   to the left of    1
12    4  to the right of    8
13    5   to the left of    1
14    5   to the left of    2
15    7   to the left of    1
16    7   to the left of    2
17    8   to the left of    4