What color is the vehicle to the right of the backpack?
The train is silver.
    src        edge_attr  dst
0     0   to the left of    8
1     0   to the left of    7
2     2  to the right of    5
3     2  to the right of    4
4     2   to the left of    7
5     2  to the right of    6
6     3               on    2
7     3   to the left of    7
8     3  to the right of    4
9     4   to the left of    2
10    4   to the left of    7
11    4   to the left of    3
12    5   to the left of    7
13    5   to the left of    2
14    5   to the left of   11
15    5          wearing    1
16    6   to the left of    7
17    6   to the left of    2
18    6   to the left of   11
19    7  to the right of   12
20    7  to the right of   10
21    7  to the right of    9
22    7  to the right of    4
23    7  to the right of    3
24    7  to the right of    0
25    7  to the right of    2
26    7  to the right of    6
27    7  to the right of    5
28    7  to the right of   11
29    8  to the right of    0
30    8  to the right of    9
31    9   to the left of    7
32    9   to the left of    8
33   10   to the left of    7
34   11  to the right of    5
35   11  to the right of    6
36   11   to the left of    7
37   12   to the left of    7