Are there either any fences or cows?
Yes, there is a cow.
    src       edge_attr  dst
0     0              of    5
1     0  to the left of    6
2     0  to the left of    3
3     0  to the left of   15
4     2  to the left of   11
..  ...             ...  ...
73   18  to the left of   13
74   18  to the left of    8
75   19              of    5
76   19  to the left of   14
77   19  to the left of   15

[78 rows x 3 columns]