What is the color of the vehicle the railroad is in front of?
The train is blue.
    src        edge_attr  dst
0     0   to the left of    5
1     0   to the left of    3
2     0   to the left of   15
3     0            above    3
4     0   to the left of   11
5     1   to the left of   15
6     2             near    8
7     2   to the left of    3
8     3            below    0
9     3           behind   15
10    3           behind   10
11    3               on   10
12    3  to the right of    8
13    3  to the right of    0
14    3  to the right of   13
15    3  to the right of    7
16    3   to the left of   14
17    3  to the right of    2
18    4   on the side of   10
19    4   to the left of   10
20    5   on the side of   10
21    5  to the right of    0
22    5  to the right of   10
23    6  to the right of   13
24    6  to the right of    7
25    7   to the left of    3
26    7   to the left of    6
27    8             near    2
28    8   to the left of   11
29    8   to the left of    3
30    8   to the left of   15
31   10  to the right of    4
32   10   to the left of    5
33   11  to the right of    8
34   11  to the right of    0
35   12   to the left of   14
36   13   to the left of    6
37   13   to the left of    3
38   14  to the right of   12
39   14  to the right of   15
40   14  to the right of    3
41   15  to the right of    8
42   15  to the right of    1
43   15   to the left of   14
44   15  to the right of    0