What is the color of the trees?
The trees are brown.
     src        edge_attr  dst
0      0   to the left of   21
1      0   to the left of   15
2      0  to the right of   14
3      0  to the right of   20
4      0  to the right of   17
..   ...              ...  ...
100   21  to the right of    0
101   21  to the right of   12
102   21  to the right of   17
103   21  to the right of   20
104   21  to the right of   14

[105 rows x 3 columns]