What kind of furniture is not wooden, the shelf or the desk?
The shelf is not wooden.
    src        edge_attr  dst
0     0  to the right of   11
1     1  to the right of   11
2     2               on    3
3     7               in    4
4     8   to the left of    9
5     8   to the left of   12
6     9               on    7
7     9   to the left of   13
8     9  to the right of    8
9     9        on top of    7
10   10  to the right of   13
11   11               on    7
12   11   to the left of    0
13   11   to the left of    1
14   11   to the left of   12
15   12        on top of    9
16   12               on    9
17   12  to the right of    8
18   12  to the right of   11
19   13               on    7
20   13  to the right of    9
21   13   to the left of   10