What material is the bridge, wood or metal?
The bridge is made of wood.
    src        edge_attr  dst
0     0   to the left of    3
1     2   to the left of    9
2     3  to the right of   16
3     3  to the right of    7
4     3  to the right of    6
5     3  to the right of    0
6     4  to the right of   16
7     4   to the left of    8
8     5   to the left of   17
9     5   to the left of   13
10    6               in    1
11    6   to the left of    3
12    7           behind   16
13    7   to the left of    3
14    7             near   16
15    8  to the right of    4
16    9  to the right of   14
17    9               by   11
18    9  to the right of    2
19    9  to the right of   11
20   10  to the right of   17
21   10  to the right of   13
22   11   to the left of    9
23   11   to the left of   19
24   11   to the left of   14
25   13  to the right of   15
26   13   to the left of   10
27   13  to the right of    5
28   14  to the right of   11
29   14   to the left of    9
30   15               on    5
31   15   to the left of   13
32   15   to the left of   17
33   16   to the left of    3
34   16             near    7
35   16      in front of    7
36   16   to the left of   20
37   16   to the left of    4
38   17   to the left of   10
39   17  to the right of    5
40   17  to the right of   15
41   19  to the right of   11
42   20  to the right of   16