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