What is the color of the bus that the person is sitting on?
The bus is blue.
    src        edge_attr  dst
0     1   to the left of   11
1     1   to the left of   10
2     1   to the left of   18
3     1               on    2
4     2   to the left of   12
5     2   to the left of   10
6     2   to the left of    9
7     2   to the left of   11
8     2   to the left of   19
9     3  to the right of    9
10    3  to the right of   11
11    3  to the right of   19
12    5   to the left of   11
13    5  to the right of    7
14    5               on    0
15    6   to the left of   15
16    7   to the left of    5
17    7   to the left of   18
18    8   to the left of   16
19    8               of   18
20    9   to the left of    3
21    9  to the right of   12
22    9  to the right of    2
23    9  to the right of   19
24   10  to the right of    1
25   10  to the right of    2
26   11               of   18
27   11  to the right of   12
28   11  to the right of    5
29   11   to the left of   13
30   11   to the left of   17
31   11  to the right of    2
32   11  to the right of    1
33   11   to the left of    3
34   12   to the left of   11
35   12   to the left of   13
36   12  to the right of    2
37   12   to the left of    9
38   12   to the left of   19
39   13  to the right of   12
40   13  to the right of   11
41   14        on top of    0
42   15  to the right of    6
43   16  to the right of    8
44   16               of   18
45   17  to the right of   11
46   18         carrying    3
47   18  to the right of    1
48   18  to the right of    7
49   19       sitting on   18
50   19   to the left of    9
51   19  to the right of    2
52   19  to the right of   12
53   19   to the left of    3