Is the fence in the bottom or in the top?
The fence is in the bottom of the image.
    src        edge_attr  dst
0     3  to the right of   14
1     3  to the right of   12
2     3  to the right of    5
3     4   to the left of   17
4     5   to the left of   16
5     5   to the left of    3
6     5   to the left of    9
7     6   to the left of    9
8     6  to the right of   11
9     9  to the right of    6
10    9  to the right of    5
11    9  to the right of   17
12   11   to the left of    6
13   12   to the left of   16
14   12   to the left of    3
15   14   to the left of    3
16   16  to the right of    5
17   16  to the right of   12
18   17   to the left of    9
19   17  to the right of    4