Which side are the papers on?
The papers are on the left of the image.
     src        edge_attr  dst
0      0  to the right of    8
1      0  to the right of   15
2      0  to the right of   27
3      0  to the right of   18
4      0   to the left of   16
..   ...              ...  ...
138   28   to the left of    2
139   28   to the left of   17
140   28   to the left of   14
141   28   to the left of   12
142   28   to the left of   19

[143 rows x 3 columns]