What vehicle is to the left of the vehicle that looks gray?
The vehicle is a locomotive.
    src        edge_attr  dst
0     0  to the right of    7
1     0  to the right of   10
2     0  to the right of    3
3     0  to the right of   11
4     1   to the left of    7
5     1   to the left of   10
6     1   to the left of    3
7     1   to the left of    4
8     3  to the right of    1
9     3   to the left of    0
10    3  to the right of   11
11    3  to the right of   10
12    3   to the left of    6
13    3  to the right of    4
14    3   to the left of    5
15    4  to the right of    1
16    4   to the left of    5
17    4   to the left of    3
18    4  to the right of   10
19    5  to the right of    3
20    5  to the right of    7
21    5  to the right of   10
22    5   to the left of    6
23    5  to the right of    4
24    6  to the right of    3
25    6  to the right of    5
26    6  to the right of    7
27    6           beside    5
28    7  to the right of   11
29    7  to the right of   10
30    7  to the right of    1
31    7   to the left of    0
32    7   to the left of    5
33    7   to the left of    6
34   10  to the right of   11
35   10   to the left of    7
36   10   to the left of    3
37   10   to the left of    0
38   10  to the right of    1
39   10   to the left of    4
40   10   to the left of    5
41   11   to the left of    3
42   11   to the left of    7
43   11   to the left of    0
44   11   to the left of   10