Do you see either any envelopes or knife blocks?
No, there are no knife blocks or envelopes.
    src        edge_attr  dst
0     1  to the right of   13
1     1  to the right of    8
2     1   to the left of    9
3     1  to the right of    6
4     1  to the right of    7
5     2  to the right of    5
6     4   to the left of    7
7     4   to the left of   13
8     4   to the left of    8
9     5   to the left of   10
10    5  to the right of   14
11    5   to the left of    2
12    6   to the left of    8
13    6   to the left of    1
14    7  to the right of    4
15    7   to the left of    1
16    7  to the right of   12
17    7  to the right of   11
18    7   to the left of    8
19    8   to the left of    1
20    8  to the right of    7
21    8  to the right of   12
22    8  to the right of    6
23    8  to the right of    4
24    9  to the right of   10
25    9  to the right of    1
26   10  to the right of   15
27   10  to the right of   14
28   10   to the left of    9
29   10  to the right of    5
30   11   to the left of   13
31   11   to the left of    7
32   12   to the left of    8
33   12   to the left of    7
34   13  to the right of    4
35   13   to the left of    1
36   13  to the right of   11
37   13  to the right of   15
38   14   to the left of   10
39   14  to the right of   15
40   14   to the left of    5
41   15   to the left of   10
42   15   to the left of   13
43   15   to the left of   14