What is the light bulb on?
The light bulb is on the wall.
    src        edge_attr  dst
0     0   to the left of    7
1     0  to the right of    3
2     0  to the right of    5
3     1               on   13
4     1  to the right of   10
5     2  to the right of    5
6     3   to the left of    7
7     3   to the left of    0
8     3   to the left of    9
9     3   to the left of   16
10    5   to the left of    7
11    5   to the left of    2
12    5   to the left of    9
13    5   to the left of    0
14    5   to the left of   16
15    6               on   12
16    6   to the left of   13
17    6   to the left of   14
18    7   to the left of   16
19    7  to the right of    0
20    7  to the right of    5
21    7  to the right of    3
22    8   to the left of   17
23    9  to the right of    3
24    9               on   16
25    9  to the right of    5
26   10   to the left of   15
27   10   to the left of   13
28   10   to the left of    1
29   10   to the left of   14
30   11   to the left of   17
31   13  to the right of   10
32   13  to the right of    6
33   14  to the right of    6
34   14  to the right of   10
35   15  to the right of   10
36   16  to the right of    5
37   16  to the right of    3
38   16  to the right of    7
39   17  to the right of   11
40   17  to the right of    8