Which side is the tower on?
The tower is on the left of the image.
    src        edge_attr  dst
0     1  to the right of   14
1     2  to the right of    5
2     2  to the right of    8
3     3   to the left of    8
4     4   to the left of   17
5     4   to the left of   16
6     4               on   13
7     5   to the left of   12
8     5  to the right of    8
9     5   to the left of    2
10    6   to the left of    8
11    7   to the left of   16
12    7   to the left of   17
13    8   to the left of   18
14    8   to the left of    2
15    8  to the right of    3
16    8  to the right of    6
17    8   to the left of    5
18    9  to the right of   14
19   11  to the right of   18
20   12  to the right of   18
21   12  to the right of    5
22   13   to the left of   16
23   13               on   15
24   13   to the left of   17
25   14   to the left of    1
26   14   to the left of    9
27   15   to the left of   16
28   15   to the left of   17
29   16  to the right of    4
30   16  to the right of    7
31   16  to the right of   13
32   16  to the right of   15
33   17  to the right of    7
34   17  to the right of    4
35   17  to the right of   13
36   17  to the right of   15
37   18   to the left of   11
38   18  to the right of    8
39   18   to the left of   12