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