What color do the flags have?
The flags have red color.
    src        edge_attr  dst
0     0               in   12
1     2               on   15
2     2  to the right of   13
3     2  to the right of   10
4     3        flying in   12
5     3               in   12
6     4        flying in   12
7     4               in   12
8     5               in   12
9     5   to the left of   15
10    6        flying in   12
11    6               in   12
12    6   to the left of   15
13    7        parked by   10
14    7  to the right of    9
15    8  to the right of   10
16    8  to the right of   13
17    9   to the left of    7
18    9   to the left of   13
19   10  to the right of   13
20   10   to the left of    8
21   10   to the left of   15
22   10   to the left of   14
23   10   to the left of    2
24   13   to the left of    8
25   13   to the left of    2
26   13   to the left of   10
27   13  to the right of    9
28   13   to the left of   15
29   13   to the left of   14
30   14  to the right of   10
31   14  to the right of   13
32   15  to the right of    5
33   15  to the right of    6
34   15  to the right of   10
35   15  to the right of   13
36   16               on   15
37   17        flying in   12
38   17               in   12