What is on the stop sign?
The letters are on the stop sign.
    src        edge_attr  dst
0     0  to the right of    1
1     0               on    4
2     1   to the left of    0
3     1  to the right of    7
4     1   to the left of    6
5     2        on top of    3
6     2   to the left of    8
7     2   to the left of    6
8     2            above    4
9     4      in front of    5
10    5           behind    4
11    6  to the right of    2
12    6  to the right of    1
13    7   to the left of    1
14    7  on the front of    4
15    8  to the right of    2