Which place is it?
It is a road.
   src        edge_attr  dst
0    0  to the right of    4
1    1   to the left of    3
2    2   to the left of    3
3    3  to the right of    2
4    3  to the right of    1
5    3  to the right of    5
6    4   to the left of    0
7    5   to the left of    3