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