What is the sign in front of the tree that is not short?
The sign is a stop sign.
    src        edge_attr  dst
0     0               of    1
1     0   to the left of    9
2     0   to the left of    1
3     1  to the right of    9
4     1           behind    3
5     1  to the right of    0
6     3      in front of    1
7     4  to the right of   10
8     7               in    5
9     7  to the right of    8
10    8   to the left of    7
11    9   to the left of    1
12    9  to the right of    0
13   10   to the left of    4