What is this fence made of?
The fence is made of metal.
    src        edge_attr  dst
0     0               on    7
1     1               on    3
2     1   to the left of    8
3     1   to the left of    2
4     2               of    8
5     2  to the right of    3
6     2  to the right of    1
7     3   to the left of    8
8     3               of    6
9     3   to the left of    2
10    4  to the right of   11
11    4  to the right of    6
12    6      in front of   12
13    6   to the left of    8
14    6   to the left of    4
15    6           behind    9
16    6          wearing    1
17    7               of    8
18    8          licking    6
19    8  to the right of    3
20    8         touching    6
21    8  to the right of    6
22    8  to the right of    1
23    9      in front of   12
24    9      in front of    6
25    9           beside    6
26   11   to the left of    4
27   11               of    6
28   12           behind    9
29   12           behind    6