Is the signal light in the bottom or in the top part?
The signal light is in the top of the image.
    src        edge_attr  dst
0     0   to the left of   21
1     0  to the right of    5
2     0   to the left of    4
3     0   to the left of   20
4     0   to the left of    8
5     1   to the left of   19
6     2  to the right of    7
7     4  to the right of    0
8     4  to the right of   16
9     4  to the right of    5
10    5   to the left of    4
11    5   to the left of    0
12    5   to the left of   20
13    5   to the left of   16
14    7   to the left of    2
15    8  to the right of   18
16    8   to the left of    9
17    8  to the right of    0
18    8   to the left of   21
19    9  to the right of    8
20    9   to the left of   11
21    9  to the right of   18
22    9  to the right of   21
23   10  to the right of   14
24   10  to the right of   15
25   11  to the right of    9
26   11  to the right of   17
27   11  to the right of   21
28   12      standing on   10
29   12  to the right of   17
30   12  to the right of   14
31   13  to the right of   14
32   13  to the right of   15
33   14   to the left of   13
34   14   to the left of   12
35   14   to the left of   10
36   15   to the left of   13
37   15   to the left of   10
38   16   to the left of   20
39   16   to the left of    4
40   16  to the right of    5
41   17   to the left of   11
42   17   to the left of   12
43   18   to the left of    9
44   18   to the left of   21
45   18   to the left of    8
46   19  to the right of    1
47   20  to the right of    5
48   20  to the right of    0
49   20  to the right of   16
50   21   to the left of    9
51   21  to the right of    8
52   21  to the right of   18
53   21   to the left of   11
54   21  to the right of    0