What kind of vehicle is it?
The vehicle is a wagon.
    src        edge_attr  dst
0     1          holding    3
1     1        pulled by    2
2     1  to the right of    7
3     2        on top of   14
4     2   to the left of   13
5     2   to the left of   12
6     2   to the left of   11
7     2          pulling    1
8     2      attached to    1
9     2  to the right of    6
10    2   to the left of    3
11    3  to the right of    4
12    3  to the right of    2
13    3  to the right of    7
14    3   to the left of    5
15    3   to the left of   10
16    3   to the left of   12
17    4   to the left of    3
18    4  to the right of    6
19    4   to the left of   13
20    4  to the right of    8
21    5  to the right of    3
22    5  to the right of   13
23    6   to the left of    2
24    6   to the left of    4
25    6   to the left of    8
26    7   to the left of   11
27    7   to the left of    1
28    7   to the left of    3
29    7   to the left of    9
30    7   to the left of   13
31    8   to the left of    4
32    8  to the right of    6
33    9  to the right of    7
34    9   to the left of   13
35   10  to the right of    3
36   10  to the right of   11
37   10           riding    1
38   10  to the right of   13
39   11  to the right of    7
40   11  to the right of    2
41   11   to the left of   10
42   12  to the right of    3
43   12  to the right of   13
44   12  to the right of    2
45   13   to the left of   10
46   13  to the right of    9
47   13  to the right of    2
48   13   to the left of    5
49   13  to the right of    4
50   13  to the right of    7
51   13   to the left of   12