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