What is the lamp on?
The lamp is on the desk.
    src        edge_attr  dst
0     0               by   15
1     0   to the left of    1
2     1   to the left of   17
3     1  to the right of    0
4     1  to the right of    2
5     2   to the left of    1
6     2               on    3
7     4  to the right of   12
8     4               on   15
9     6  to the right of   12
10    7  to the right of   10
11    8   to the left of   12
12    9   to the left of   12
13   10   to the left of    7
14   10  to the right of   11
15   10  to the right of   16
16   11   to the left of   13
17   11   to the left of   10
18   12  to the right of    8
19   12  to the right of    9
20   12   to the left of    6
21   12   to the left of    4
22   13               on   17
23   13  to the right of   11
24   16   to the left of   10
25   17  to the right of    1