Is the ground sandy or snowy?
The ground is snowy.
    src        edge_attr  dst
0     0  to the right of    6
1     0  to the right of   11
2     1   to the left of    6
3     2   to the left of    6
4     3       covered by    7
5     4   to the left of    5
6     5  to the right of    4
7     6  to the right of    2
8     6   to the left of   10
9     6   to the left of   11
10    6   to the left of    0
11    6  to the right of    1
12    7         covering    3
13    8      in front of    9
14    9           behind    8
15   10  to the right of   11
16   10  to the right of    6
17   11   to the left of   10
18   11   to the left of    0
19   11  to the right of    6