Who is on the surfboard?
The surfer is on the surfboard.
    src        edge_attr  dst
0     0               on    9
1     3           behind   10
2     4  to the right of    7
3     4  to the right of   13
4     5  to the right of    7
5     5  to the right of   13
6     5               on    4
7     6               on   11
8     6  to the right of    7
9     7   to the left of    5
10    7   to the left of   11
11    7   to the left of    4
12    7   to the left of    6
13   10               on   13
14   10      in front of    3
15   11  to the right of    7
16   13   to the left of    4
17   13   to the left of    5
18   14  to the right of   15
19   15   to the left of   14