What is the sidewalk made of?
The side walk is made of concrete.
    src        edge_attr  dst
0     0  to the right of   11
1     0   to the left of    7
2     0   to the left of    6
3     0  to the right of    8
4     1  to the right of   28
5     3   to the left of   21
6     4  to the right of   10
7     4  to the right of   12
8     4  to the right of    5
9     5  to the right of    8
10    5  to the right of   10
11    5   to the left of    4
12    6  to the right of    7
13    6  to the right of    0
14    7  to the right of    0
15    7   to the left of    6
16    7  to the right of   11
17    8   to the left of   21
18    8      in front of   28
19    8   to the left of    5
20    8  to the right of   28
21    8   to the left of    0
22    8   to the left of   10
23    8   to the left of   11
24   10   to the left of    5
25   10  to the right of    8
26   10   to the left of    4
27   11   to the left of    0
28   11  to the right of    8
29   11   to the left of    7
30   11  to the right of   23
31   12           behind   29
32   12          wearing   16
33   12   to the left of    4
34   12               in   29
35   14  to the right of   15
36   15   to the left of   14
37   15  to the right of   26
38   16               on   12
39   16  to the right of   27
40   17           beside   20
41   21      in front of   28
42   21  to the right of    3
43   21  to the right of    8
44   21  to the right of   23
45   21  to the right of   24
46   22   to the left of   23
47   23   to the left of   21
48   23   to the left of   11
49   23  to the right of   22
50   24   to the left of   21
51   26   to the left of   15
52   27   to the left of   16
53   28   to the left of    8
54   28   to the left of    1
55   28           behind   21
56   28           behind    8
57   29      in front of   12