What is the floor covered by?
The floor is covered by the water.
    src        edge_attr  dst
0     0  to the right of   19
1     0  to the right of   17
2     0   to the left of    7
3     0  to the right of    1
4     0   to the left of   12
..  ...              ...  ...
75   20  to the right of   17
76   21   to the left of   12
77   21   to the left of   11
78   21   to the left of    7
79   21  to the right of    1

[80 rows x 3 columns]