Which kind of vehicle is not red?
The vehicle is a truck.
    src        edge_attr  dst
0     0   to the left of   11
1     0   to the left of    6
2     1  to the right of   11
3     1  to the right of    8
4     1   to the left of    3
5     1  to the right of   17
6     1  to the right of    2
7     2   to the left of    1
8     2   to the left of   12
9     3  to the right of    4
10    3  to the right of    1
11    3  to the right of   10
12    4   to the left of    3
13    6  to the right of    0
14    6  to the right of    8
15    6  to the right of   17
16    7   to the left of   18
17    7  to the right of   13
18    8   to the left of    1
19    8   to the left of   10
20    8   to the left of    6
21    9  to the right of   15
22    9  to the right of   16
23    9   to the left of   18
24   10   to the left of    3
25   10  to the right of    8
26   10  to the right of   17
27   11  to the right of    0
28   11   to the left of    1
29   12  to the right of   17
30   12  to the right of    2
31   13   to the left of   14
32   13   to the left of   15
33   13   to the left of    7
34   13   to the left of   16
35   14  to the right of   13
36   14  to the right of   16
37   14  to the right of   15
38   15  to the right of   13
39   15   to the left of   14
40   15   to the left of    9
41   16  to the right of   13
42   16   to the left of   14
43   16   to the left of    9
44   17   to the left of   12
45   17   to the left of   10
46   17   to the left of    6
47   17   to the left of    1
48   18  to the right of    7
49   18  to the right of    9