Which kind of furniture is made of glass?
The furniture is a desk.
    src        edge_attr  dst
0     0   to the left of    5
1     0   to the left of   13
2     1  to the right of   13
3     1   to the left of    9
4     2  to the right of   13
5     2  to the right of   14
6     3   to the left of   15
7     3  to the right of   14
8     5  to the right of    0
9     6   to the left of   15
10    7  to the right of   13
11    8   to the left of   17
12    8   to the left of   12
13    9  to the right of   13
14    9  to the right of    1
15   11   to the left of   12
16   11   to the left of   16
17   12  to the right of    8
18   12  to the right of   11
19   12  to the right of   17
20   13  to the right of    0
21   13   to the left of    9
22   13   to the left of    1
23   13   to the left of    7
24   13   to the left of    2
25   13               on   10
26   14   to the left of   15
27   14   to the left of    3
28   14   to the left of    2
29   15  to the right of   14
30   15  to the right of    6
31   15  to the right of    3
32   16  to the right of   11
33   17   to the left of   12
34   17  to the right of    8