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