What is the sign in front of the fence on the left?
The sign is a stop sign.
    src        edge_attr  dst
0     0      in front of   15
1     0   to the left of   10
2     0  to the right of    5
3     0            above   14
4     0      in front of    8
5     1               on    0
6     2   to the left of    6
7     2   to the left of    3
8     3   to the left of   10
9     3  to the right of    6
10    3  to the right of    2
11    4   to the left of   11
12    5   to the left of    0
13    5               of    4
14    5   to the left of   11
15    5   to the left of    9
16    6               on    0
17    6  to the right of    2
18    6   to the left of    3
19    7   to the left of   14
20    7   to the left of   12
21    7  to the right of   15
22    8           behind    0
23    9               in    0
24    9  to the right of    5
25    9   to the left of   10
26   10  to the right of   13
27   10  to the right of   12
28   10  to the right of    9
29   10  to the right of    0
30   10  to the right of   14
31   10  to the right of    3
32   11  to the right of    5
33   11  to the right of    4
34   12  to the right of    7
35   12   to the left of   10
36   13               on    0
37   13  to the right of   15
38   13   to the left of   10
39   14   to the left of   10
40   14       underneath    0
41   14  to the right of    7
42   15   to the left of    7
43   15   to the left of   13
44   15           behind    0