What's located on top of the table?
The paper is on top of the table.
    src        edge_attr  dst
0     0   to the left of   15
1     0  to the right of    3
2     0   to the left of   12
3     1        on top of    2
4     3   to the left of    0
5     3   to the left of   15
6     3  to the right of   13
7     3   to the left of    6
8     3   to the left of    4
9     3   to the left of   12
10    3   to the left of    7
11    4  to the right of    3
12    5   to the left of   12
13    5   to the left of    6
14    5   to the left of   15
15    6  to the right of    5
16    6  to the right of    3
17    6   to the left of   15
18    7   to the left of   12
19    7  to the right of    3
20    7   to the left of   15
21    8  to the right of    9
22    9   to the left of    8
23   10   to the left of   11
24   10   to the left of   17
25   11  to the right of   10
26   12  to the right of    5
27   12  to the right of    7
28   12  to the right of    0
29   12  to the right of    3
30   13   to the left of    3
31   15  to the right of    3
32   15  to the right of    5
33   15  to the right of    6
34   15  to the right of    7
35   15  to the right of    0
36   17  to the right of   10