Are there either cows or fences?
Yes, there is a cow.
    src        edge_attr  dst
0     0               of    3
1     0   to the left of   14
2     1  to the right of    4
3     1               of    3
4     2   to the left of    5
5     3  to the right of   12
6     4   to the left of    1
7     4   to the left of   13
8     5  to the right of    2
9     5   to the left of   19
10    6  to the right of   16
11    6  to the right of   11
12    6  to the right of   18
13    6  to the right of   10
14    9   to the left of   18
15   10   to the left of   19
16   10   to the left of    6
17   11   to the left of   19
18   11   to the left of    6
19   12   to the left of    3
20   13  to the right of    4
21   13               on    1
22   14  to the right of    0
23   14   to the left of   19
24   15               on    0
25   15               on    3
26   16   to the left of   19
27   16   to the left of    6
28   18  to the right of    9
29   18   to the left of    6
30   19  to the right of   14
31   19  to the right of   16
32   19  to the right of    5
33   19  to the right of   11
34   19  to the right of   10