Are the flags red?
Yes, the flags are red.
    src        edge_attr  dst
0     0   to the left of   10
1     0   to the left of    1
2     1   to the left of    4
3     1   to the left of    6
4     1  to the right of   18
..  ...              ...  ...
78   20  to the right of    1
79   21   to the left of    1
80   21   to the left of   20
81   21  to the right of    7
82   21             near    7

[83 rows x 3 columns]