What is the rock covered by?
The rock is covered by the snow.
    src        edge_attr  dst
0     0   to the left of    4
1     1   to the left of    4
2     2               on    7
3     2  to the right of    3
4     3        on top of   12
5     3               on   12
6     3   to the left of    7
7     3   to the left of    2
8     4  to the right of    0
9     4  to the right of    5
10    4  to the right of    1
11    5   to the left of    4
12    6       covered in    9
13    6               in    9
14    6               on    9
15    7            below   12
16    7  to the right of    3
17    9               on   12
18   10   to the left of   14
19   11         covering   14
20   12       covered in   11
21   12       covered in    9
22   13          wearing    1
23   13          wearing    8
24   13               on    6
25   13        on top of   12
26   13          wearing   10
27   13          wearing    0
28   13       looking at   12
29   13          wearing    5
30   13          wearing    4
31   14  to the right of   10
32   14       covered by   11