What is the bench in front of the shrub made of?
The bench is made of metal.
    src        edge_attr  dst
0     0   to the left of    2
1     1  to the right of   17
2     1  to the right of   19
3     2  to the right of    0
4     3          next to    6
5     3             near    6
6     3   to the left of    7
7     5   to the left of    9
8     5   to the left of   19
9     5           behind   12
10    5   to the left of   17
11    5  growing next to   18
12    6             near    3
13    7  to the right of   14
14    7  to the right of    3
15    7  to the right of    8
16    8   to the left of    7
17    9  to the right of    5
18    9   to the left of   18
19   10   to the left of   19
20   10  to the right of   15
21   11  to the right of   15
22   11       hanging on    9
23   11   to the left of   19
24   12            above    1
25   12      in front of    5
26   14   to the left of    7
27   15   to the left of   17
28   15   to the left of   10
29   15   to the left of   11
30   17          reading   13
31   17       sitting on   12
32   17          holding   13
33   17          wearing   11
34   17          wearing    0
35   17  to the right of    5
36   17   to the left of   18
37   17  to the right of   15
38   17   to the left of    1
39   18  to the right of   17
40   18  to the right of   19
41   18   to the left of   20
42   18  to the right of    9
43   19   to the left of    1
44   19  to the right of    5
45   19  to the right of   11
46   19  to the right of   10
47   19   to the left of   18
48   20  to the right of   18