What kind of device is on top of the table?
The device is a computer mouse.
    src        edge_attr  dst
0     0  to the right of    6
1     1  to the right of    6
2     2   to the left of    7
3     2        on top of    8
4     2               on    8
5     3        on top of    9
6     4  to the right of    6
7     4  to the right of   11
8     5  to the right of   11
9     6   to the left of   10
10    6   to the left of    1
11    6               at    8
12    6   to the left of    0
13    6   to the left of    4
14    7  to the right of    2
15    7               on    8
16    9               on    8
17   10               at    8
18   10  to the right of   11
19   10  to the right of    6
20   11   to the left of   12
21   11   to the left of    5
22   11   to the left of    4
23   11   to the left of   10
24   12  to the right of   11