Is the blue sky empty or full?
The sky is full.
    src        edge_attr  dst
0     1   to the left of   12
1     1   to the left of    7
2     1  to the right of   20
3     1          wearing    2
4     2   to the left of    7
5     2  to the right of   20
6     2   to the left of   12
7     4        flying in   17
8     4  to the right of   18
9     5  to the right of    6
10    6   to the left of    5
11    7  to the right of    1
12    7  to the right of   20
13    7  to the right of    8
14    7  to the right of    2
15    8  to the right of   20
16    8   to the left of    7
17    8   to the left of   12
18    9               on    0
19   10   to the left of   11
20   11               on    0
21   11  to the right of   10
22   11   to the left of   20
23   12  to the right of   20
24   12  to the right of    8
25   12               on    0
26   12  to the right of    1
27   12  to the right of    2
28   13   to the left of   20
29   16        flying in   17
30   16               in   17
31   18        flying in   17
32   18   to the left of    4
33   20  to the right of   11
34   20   to the left of   12
35   20  to the right of   13
36   20   to the left of    1
37   20   to the left of    2
38   20   to the left of    7
39   20   to the left of    8
40   20   to the left of   21
41   21  to the right of   20