Who is looking down?
The zebras are looking down.
    src         edge_attr  dst
0     0   to the right of    4
1     0   to the right of    7
2     0   to the right of   17
3     2    to the left of   15
4     2   to the right of   11
5     2   to the right of    6
6     3   to the right of    4
7     3   to the right of   17
8     3   to the right of   11
9     4    to the left of    0
10    4   to the right of   17
11    4    to the left of    3
12    5    to the left of    6
13    6    to the left of    2
14    6   to the right of    5
15    7   to the right of   11
16    7    to the left of    0
17    7   to the right of   17
18    8   to the right of   16
19    8    to the left of   15
20    8    to the left of   10
21   10   to the right of    8
22   11    to the left of    7
23   11    to the left of    2
24   11    to the left of    3
25   12  on the bottom of    1
26   12   to the right of   13
27   12                by    0
28   13    to the left of   12
29   15   to the right of    8
30   15   to the right of   16
31   15   to the right of    2
32   16    to the left of   15
33   16    to the left of    8
34   17    to the left of    3
35   17    to the left of    7
36   17    to the left of    4
37   17    to the left of    0