Which place is it?
It is a station.
    src        edge_attr  dst
0     0   to the left of    9
1     0   to the left of    8
2     0   to the left of    3
3     0   to the left of    2
4     0   to the left of    4
5     1  to the right of    7
6     2  to the right of    0
7     2  to the right of   10
8     3  to the right of    0
9     3  to the right of   10
10    4  to the right of    0
11    4   to the left of    8
12    4  to the right of   10
13    7   to the left of   12
14    7   to the left of    1
15    8  to the right of    0
16    8  to the right of    4
17    9  to the right of    0
18   10   to the left of    3
19   10   to the left of    2
20   10   to the left of    4
21   12  to the right of    7