What color is the sand?
The sand is gray.
    src        edge_attr  dst
0     0  to the right of    6
1     1  to the right of    4
2     1  to the right of   14
3     2   to the left of   14
4     2   to the left of   11
5     4  to the right of   11
6     4   to the left of    1
7     5   to the left of   15
8     6   to the left of    0
9     7  to the right of   12
10   11  to the right of   15
11   11  to the right of   17
12   11   to the left of    4
13   11   to the left of   14
14   11  to the right of    2
15   12   to the left of    7
16   14  to the right of    2
17   14  to the right of   11
18   14  to the right of   17
19   14   to the left of    1
20   15  to the right of    5
21   15   to the left of   11
22   17   to the left of   14
23   17   to the left of   11