Is the brown curtain on the left side or on the right?
The curtain is on the left of the image.
    src        edge_attr  dst
0     0  to the right of    9
1     0  to the right of    2
2     0   to the left of   12
3     2   to the left of    3
4     2   to the left of    0
5     3  to the right of    2
6     3   to the left of   12
7     3  to the right of    9
8     5  to the right of    7
9     6   to the left of    7
10    6   to the left of   12
11    7   to the left of   12
12    7   to the left of    5
13    7  to the right of    6
14    9   to the left of    0
15    9   to the left of    3
16   10               on    4
17   12  to the right of    3
18   12  to the right of    0
19   12  to the right of    7
20   12  to the right of    6