Which kind of material was used to make the ladder?
The ladder is made of wood.
    src        edge_attr  dst
0     0   to the left of   10
1     0   to the left of    2
2     0   to the left of    4
3     0   to the left of    3
4     0   to the left of    8
..  ...              ...  ...
65   12  to the right of    9
66   12  to the right of    2
67   12  to the right of    7
68   12  to the right of    8
69   13  to the right of    1

[70 rows x 3 columns]