Where is the fence?
The fence is on the hill.
    src        edge_attr  dst
0     0   to the left of    6
1     0   to the left of    3
2     0   to the left of   20
3     0   to the left of    8
4     0   to the left of    7
..  ...              ...  ...
73   20  to the right of   15
74   20  to the right of    0
75   21  to the right of   12
76   21               on   10
77   21  to the right of    7

[78 rows x 3 columns]