What color is the marker in the box?
The marker is blue.
    src        edge_attr  dst
0     0  to the right of    6
1     0   to the left of   13
2     0               in    1
3     0   to the left of    5
4     1   to the left of   13
5     1  to the right of    6
6     2  to the right of    6
7     2   to the left of   13
8     2               on   15
9     5  to the right of    0
10    6   to the left of    1
11    6               on    3
12    6   to the left of    0
13    6   to the left of   15
14    6   to the left of    2
15    6   to the left of   10
16    8               in    5
17   10  to the right of    6
18   10   to the left of   13
19   10   to the left of   11
20   11  to the right of   10
21   13  to the right of    0
22   13  to the right of    1
23   13  to the right of   15
24   13  to the right of    2
25   13  to the right of   10
26   15               on    3
27   15   to the left of   13
28   15  to the right of    6