What is the material of the fence?
The fence is made of metal.
    src        edge_attr  dst
0     1  to the right of   11
1     1   to the left of   15
2     1  to the right of   10
3     1   to the left of    6
4     1   to the left of   14
..  ...              ...  ...
62   17  to the right of    6
63   17  to the right of    9
64   18  to the right of    4
65   18   to the left of    5
66   18  to the right of    9

[67 rows x 3 columns]