Is the ground that is not dirty made of asphalt or rubber?
The ground is made of rubber.
    src        edge_attr  dst
0     0  to the right of   11
1     2  to the right of    7
2     3   to the left of    5
3     3  to the right of    8
4     3  to the right of   11
5     4   to the left of    9
6     4   to the left of    7
7     5  to the right of    3
8     5  to the right of    8
9     6  to the right of    7
10    7  to the right of   11
11    7   to the left of    2
12    7   to the left of    6
13    7  to the right of    4
14    8   to the left of    5
15    8   to the left of    3
16    8  to the right of   11
17    9  to the right of    4
18   11   to the left of    7
19   11   to the left of    0
20   11   to the left of    3
21   11   to the left of    8