Which color is the trashcan?
The trashcan is green.
    src        edge_attr  dst
0     0   to the left of    2
1     1   to the left of    8
2     1   to the left of    2
3     2  to the right of    1
4     2  to the right of    0
5     2  to the right of    8
6     2  to the right of    3
7     2  to the right of    9
8     3   to the left of    2
9     4   to the left of    5
10    4   to the left of    6
11    4   to the left of   14
12    4   to the left of   13
13    5  to the right of    4
14    6  to the right of    4
15    8  to the right of    1
16    8   to the left of    2
17    9   to the left of    2
18   10  to the right of   15
19   13  to the right of    4
20   14  to the right of    4
21   15   to the left of   10