Where is the grass?
The grass is on the runway.
    src        edge_attr  dst
0     1   to the left of   15
1     1  to the right of   13
2     1   to the left of    2
3     1   to the left of   12
4     1               by    4
5     2   to the left of   15
6     2  to the right of    3
7     2  to the right of    1
8     2  to the right of    5
9     2  to the right of   13
10    3   to the left of    2
11    5   to the left of   15
12    5   to the left of   12
13    5   to the left of    2
14    5  to the right of   13
15    7  to the right of    9
16    9  to the right of   14
17    9   to the left of    7
18   10               on    8
19   12  to the right of    1
20   12   to the left of   15
21   12  to the right of   13
22   12  to the right of    5
23   13   to the left of    1
24   13   to the left of    5
25   13   to the left of   12
26   13   to the left of    2
27   14   to the left of    9
28   15  to the right of    2
29   15  to the right of   12
30   15  to the right of    1
31   15  to the right of    5