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