Do you see any zebras?
No, there are no zebras.
    src        edge_attr  dst
0     0  to the right of    9
1     4   to the left of   10
2     5               on    9
3     5  to the right of   11
4     6   to the left of    8
5     6   to the left of    7
6     7  to the right of   11
7     7  to the right of    6
8     8  to the right of    6
9     9   to the left of    0
10   10  to the right of    4
11   11   to the left of    7
12   11   to the left of    5
13   11   to the left of   12
14   12  to the right of   11