Are the stones made of rock?
Yes, the stones are made of rock.
    src        edge_attr  dst
0     0   to the left of   11
1     0   to the left of   12
2     0   to the left of    7
3     1   to the left of    5
4     2  to the right of    7
5     2  to the right of    4
6     2  to the right of    8
7     2   to the left of    6
8     2   to the left of    5
9     3  to the right of   16
10    3  to the right of   17
11    3   to the left of    5
12    4   to the left of    2
13    4   to the left of    7
14    4   to the left of   11
15    4   to the left of   12
16    5  to the right of   15
17    5  to the right of    7
18    5  to the right of   12
19    5  to the right of    1
20    5  to the right of   17
21    5  to the right of    3
22    5  to the right of    2
23    5  to the right of    8
24    6  to the right of    2
25    6  to the right of    8
26    6  to the right of    7
27    6  to the right of   12
28    7   to the left of    6
29    7  to the right of    0
30    7   to the left of    2
31    7  to the right of    4
32    7   to the left of    5
33    7   to the left of   12
34    8   to the left of    5
35    8   to the left of    2
36    8   to the left of    6
37   11  to the right of    4
38   11  to the right of    0
39   11   to the left of   13
40   12   to the left of    6
41   12   to the left of    5
42   12  to the right of    0
43   12  to the right of    4
44   12  to the right of    7
45   13  to the right of   11
46   15   to the left of    5
47   16   to the left of    3
48   16   to the left of   17
49   17   to the left of    5
50   17  to the right of   16
51   17   to the left of    3