Who is on the skateboard?
The boy is on the skateboard.
    src        edge_attr  dst
0     0   to the left of   12
1     2   to the left of   21
2     2  to the right of   22
3     3   to the left of    8
4     4  to the right of   22
5     4  to the right of   18
6     6   to the left of   17
7     6   to the left of    7
8     7  to the right of    6
9     8  to the right of    3
10    9  to the right of   15
11   12  to the right of    0
12   13   to the left of   17
13   15   to the left of    9
14   17  to the right of    6
15   17  to the right of   13
16   18   to the left of    4
17   19        on top of   15
18   20               on   19
19   20          wearing   13
20   20        riding on   19
21   20          wearing    1
22   20          wearing    2
23   20            using   19
24   21  to the right of    2
25   22   to the left of    4
26   22   to the left of    2