What color is the sign on the pole?
The stop sign is green.
    src        edge_attr  dst
0     1  to the right of    6
1     1  to the right of    3
2     1   to the left of   10
3     3   to the left of   10
4     3   to the left of    1
5     4               on    5
6     4  to the right of    6
7     5  to the right of    8
8     6   to the left of   10
9     6   to the left of    1
10    6   to the left of    4
11    8   to the left of    5
12    8   to the left of    9
13    9  to the right of    8
14   10  to the right of    1
15   10  to the right of    6
16   10  to the right of    3