Are there any knives?
Yes, there is a knife.
    src        edge_attr  dst
0     0   to the left of   10
1     0  to the right of    2
2     2   to the left of    0
3     2   to the left of    6
4     2   to the left of    9
5     3   to the left of    7
6     3   to the left of    5
7     3          cutting    5
8     4   to the left of    7
9     5   to the left of    8
10    5  to the right of    3
11    5   to the left of   13
12    6   to the left of   10
13    6  to the right of    9
14    6  to the right of    2
15    7  to the right of    4
16    7  to the right of    3
17    8  to the right of   14
18    8  to the right of   15
19    8  to the right of   11
20    8  to the right of    5
21    8  to the right of   12
22    9   to the left of   10
23    9  to the right of    2
24    9   to the left of    6
25   10               on    7
26   10  to the right of    0
27   10  to the right of    9
28   10  to the right of    6
29   11   to the left of    8
30   12   to the left of    8
31   13  to the right of    5
32   13  to the right of   14
33   13               in    8
34   14   to the left of   13
35   14  to the right of   15
36   14   to the left of    8
37   15               on    7
38   15   to the left of    8
39   15   to the left of   14