Which material is the sidewalk made of?
The sidewalk is made of concrete.
    src        edge_attr  dst
0     0  to the right of   17
1     0  to the right of   12
2     0  to the right of   19
3     0  to the right of   18
4     0  to the right of    4
..  ...              ...  ...
75   23  to the right of    7
76   23  to the right of   14
77   23   to the left of   22
78   23  to the right of   13
79   24   to the left of    0

[80 rows x 3 columns]