What are the benches to the left of the box made of?
The benches are made of wood.
    src        edge_attr  dst
0     0            above    9
1     0  to the right of   16
2     0  to the right of   15
3     1            above   15
4     3  to the right of   13
5     3  to the right of   12
6     3  to the right of   11
7     4  to the right of    7
8     4   to the left of    6
9     6  to the right of    4
10    7   to the left of    4
11    9  to the right of   16
12    9            below    0
13   11   to the left of    3
14   12   to the left of    3
15   13   to the left of    3
16   15   to the left of    0
17   15            below    1
18   16   to the left of    0
19   16   to the left of    9