On which side is the shelf?
The shelf is on the left of the image.
    src        edge_attr  dst
0     0  to the right of    4
1     0  to the right of   17
2     1               on   15
3     1   to the left of    6
4     3  to the right of   17
5     3  to the right of   14
6     3  to the right of    4
7     3  to the right of   10
8     4   to the left of    5
9     4   to the left of    6
10    4  to the right of   15
11    4   to the left of    3
12    4   to the left of    0
13    5  to the right of   17
14    5  to the right of    4
15    5  to the right of   15
16    6               in   13
17    6  to the right of    4
18    6  to the right of   10
19    6  to the right of    1
20    6  to the right of   14
21    6  to the right of   17
22    6  to the right of   15
23    7  to the right of   11
24    7   to the left of   18
25    7               of   12
26    7  to the right of   12
27    8  to the right of    9
28    9   to the left of    8
29   10  to the right of   15
30   10   to the left of    3
31   10   to the left of    6
32   11   to the left of   18
33   11  to the right of   12
34   11               on    6
35   11   to the left of    7
36   12   to the left of   11
37   12   to the left of    7
38   12               on    6
39   14  to the right of   15
40   14   to the left of    3
41   14   to the left of    6
42   15   to the left of    5
43   15   to the left of    6
44   15   to the left of    4
45   15   to the left of   10
46   15   to the left of   17
47   15   to the left of   14
48   17   to the left of    3
49   17               on    4
50   17  to the right of   15
51   17   to the left of    0
52   17   to the left of    5
53   17   to the left of    6
54   18  to the right of    7
55   18               in   13
56   18  to the right of   11