Which color is the ground?
The ground is gray.
    src        edge_attr  dst
0     0  to the right of   10
1     0  to the right of    7
2     0  to the right of    4
3     2  to the right of    3
4     2               on    7
5     3   to the left of    6
6     3   to the left of    2
7     3   to the left of   11
8     3   to the left of   10
9     4   to the left of    0
10    5   to the left of   10
11    6      in front of   10
12    6  to the right of    3
13    7      in front of   10
14    7   to the left of    0
15    8            above   10
16   10  to the right of    5
17   10  to the right of    3
18   10           behind    6
19   10           behind    7
20   10   to the left of    0
21   11               of   10
22   11  to the right of    3