What is covered in snow?
The tree is covered in snow.
    src        edge_attr  dst
0     0         covering   15
1     0   to the left of   15
2     1  to the right of   15
3     2   to the left of   14
4     2   to the left of    8
5     2  to the right of   15
6     3  to the right of   15
7     4  to the right of   15
8     4   to the left of    7
9     6  to the right of   15
10    6   to the left of    7
11    7  to the right of    8
12    7  to the right of   12
13    7  to the right of    4
14    7  to the right of    6
15    8   to the left of    7
16    8  to the right of   15
17    8  to the right of    2
18    8  to the right of   13
19    9  to the right of   15
20   11  to the right of   15
21   12          holding    8
22   12   to the left of    7
23   12          wearing    9
24   12            using    6
25   12  to the right of   15
26   13   to the left of    8
27   13  to the right of   15
28   13          holding    2
29   14  to the right of   15
30   14  to the right of    2
31   15   to the left of   17
32   15   to the left of    9
33   15       covered by    0
34   15   to the left of   14
35   15       covered in    0
36   15   to the left of    4
37   15   to the left of   11
38   15   to the left of   12
39   15   to the left of   13
40   15   to the left of    2
41   15   to the left of    8
42   15   to the left of    1
43   15   to the left of    3
44   15   to the left of    6
45   15  to the right of    0
46   15   to the left of   16
47   16  to the right of   15
48   17  to the right of   15