What material is the road, stone or cobblestone?
The road is made of stone.
    src        edge_attr  dst
0     0  to the right of    4
1     1  to the right of    8
2     2  to the right of   17
3     2  to the right of    9
4     4   to the left of    0
5     5  to the right of   19
6     6          next to   12
7     6             near   12
8     6  to the right of   12
9     6  to the right of   15
10    6  to the right of   14
11    6   to the left of   20
12    8   to the left of    1
13    9   to the left of    2
14   10  to the right of   14
15   10  to the right of   13
16   10  to the right of   11
17   10   to the left of   20
18   11   to the left of   10
19   11  to the right of   12
20   11  to the right of   14
21   11  to the right of   15
22   11   to the left of   20
23   12   to the left of   11
24   12               by    1
25   12             near    6
26   12   to the left of    6
27   13  to the right of   14
28   13   to the left of   10
29   14   to the left of    6
30   14   to the left of   13
31   14   to the left of   11
32   14   to the left of   10
33   15   to the left of   11
34   15   to the left of    6
35   15  to the right of   16
36   16   to the left of   15
37   17   to the left of    2
38   18   to the left of   19
39   19  to the right of   18
40   19   to the left of    5
41   20  to the right of    6
42   20  to the right of   10
43   20  to the right of   11