What is the person that is to the left of the backpack riding on?
The person is riding on the snowboard.
    src        edge_attr  dst
0     0   to the left of    9
1     1  to the right of   13
2     1  to the right of   11
3     1  to the right of   10
4     1  to the right of    4
5     2  to the right of    4
6     3   to the left of    9
7     3  to the right of    6
8     4   to the left of    2
9     4   to the left of    1
10    4   to the left of    5
11    5  to the right of    4
12    6               on    8
13    6   to the left of    3
14    6   to the left of    7
15    7          wearing   11
16    7               in    6
17    7        riding on    8
18    7          wearing   12
19    7          wearing    0
20    7          wearing   13
21    7               on    8
22    7   to the left of    9
23    7  to the right of    6
24    8               in    6
25    9  to the right of    0
26    9  to the right of    3
27    9  to the right of    7
28   10   to the left of    1
29   11   to the left of    1
30   13   to the left of    1