What is the hill top covered by?
The hill top is covered by the snow.
    src        edge_attr  dst
0     0   to the left of   13
1     0   to the left of   11
2     0   to the left of   15
3     1               in   14
4     2  to the right of    7
5     3  to the right of   12
6     3   to the left of    7
7     3   to the left of   10
8     4   to the left of    5
9     5   to the left of   11
10    5   to the left of   13
11    5  to the right of    6
12    5  to the right of    4
13    5       covered by    8
14    6   to the left of    5
15    7               on    8
16    7   to the left of    2
17    7  to the right of   12
18    7   running across    8
19    7  to the right of    3
20    9   on the side of    4
21   10  to the right of   12
22   10  to the right of    3
23   11  to the right of    5
24   11  to the right of    0
25   11  to the right of   15
26   12   to the left of   10
27   12   to the left of    7
28   12   to the left of    3
29   13  to the right of   15
30   13  to the right of    0
31   13  to the right of    5
32   15   to the left of   11
33   15       covered by    8
34   15  to the right of    0
35   15   to the left of   13