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