What is the fence made of?
The fence is made of wood.
    src        edge_attr  dst
0     1  to the right of    9
1     1  to the right of    2
2     1  to the right of   12
3     1  to the right of   13
4     2   to the left of   13
5     2   to the left of    1
6     2   to the left of    3
7     3  to the right of    6
8     3  to the right of    2
9     3  to the right of   12
10    3      in front of   12
11    4  to the right of   10
12    5  to the right of   10
13    6   to the left of    3
14    6  to the right of    8
15    6   to the left of   13
16    6   to the left of    9
17    7  to the right of   10
18    8               on   15
19    8   to the left of    6
20    8               in   15
21    8               in    2
22    9   to the left of    1
23    9  to the right of    6
24    9  to the right of   12
25   10   to the left of    5
26   10   to the left of    7
27   10   to the left of    4
28   11   to the left of   14
29   12   to the left of    9
30   12   to the left of   13
31   12   to the left of    1
32   12   to the left of    3
33   12               in    2
34   12           behind    3
35   12               on   15
36   13  to the right of    2
37   13   to the left of    1
38   13  to the right of   12
39   13  to the right of    6
40   14  to the right of   11
41   15               on    0