What's the sidewalk made of?
The sidewalk is made of brick.
     src        edge_attr  dst
0      0   walking behind    5
1      0  to the right of    9
2      0  to the right of   23
3      0  to the right of   10
4      0  to the right of    4
..   ...              ...  ...
115   25  to the right of    4
116   25  to the right of    1
117   25  to the right of    7
118   25  to the right of    5
119   25  to the right of   23

[120 rows x 3 columns]