Of which color is the cross?
The cross is red.
    src        edge_attr  dst
0     0   to the left of    9
1     0  to the right of   12
2     1   to the left of   15
3     1   to the left of   16
4     1   to the left of    3
5     2  to the right of   10
6     2  to the right of    6
7     3  to the right of   16
8     3  to the right of    1
9     4  to the right of   12
10    4   to the left of    9
11    6   to the left of    2
12    9  to the right of    4
13    9  to the right of    0
14   10   to the left of    2
15   11   to the left of   15
16   12   to the left of    0
17   12   to the left of    4
18   14               in   18
19   15  to the right of    1
20   15  to the right of   11
21   16   to the left of    3
22   16  to the right of    1