What vehicle is gray?
The vehicle is a car.
    src        edge_attr  dst
0     0  to the right of   10
1     0  to the right of    6
2     0  to the right of    5
3     0  to the right of    9
4     1  to the right of    6
5     1  to the right of    5
6     1  to the right of    9
7     3  to the right of   12
8     3  to the right of    5
9     5  to the right of    8
10    5   to the left of   12
11    5   to the left of    3
12    5   to the left of    0
13    5   to the left of    1
14    6   to the left of    0
15    6   to the left of    1
16    6   to the left of   12
17    7               on    2
18    8   to the left of   12
19    8   to the left of    5
20    9   to the left of    0
21    9   to the left of    1
22   10   to the left of    0
23   12               in    7
24   12  to the right of    5
25   12  to the right of    6
26   12  to the right of    8
27   12   to the left of    3