What is the color of the tall trees?
The trees are dark.
    src        edge_attr  dst
0     1   to the left of    2
1     1   to the left of    6
2     1   to the left of    9
3     2  to the right of    3
4     2  to the right of    6
5     2  to the right of    8
6     2  to the right of    9
7     2  to the right of   13
8     2  to the right of   11
9     2  to the right of    1
10    3  to the right of   12
11    3   to the left of    2
12    5               on    4
13    5   to the left of    7
14    6   to the left of    2
15    6  to the right of    1
16    7  to the right of    5
17    7  to the right of   10
18    8   to the left of    2
19    8  to the right of   12
20    9  to the right of   12
21    9  to the right of    1
22    9   to the left of    2
23   10   to the left of    7
24   10  to the right of   12
25   11  to the right of   12
26   11   to the left of    2
27   12   to the left of   10
28   12   to the left of    9
29   12   to the left of    3
30   12   to the left of   11
31   12   to the left of    8
32   12               of    1
33   13   to the left of    2