What's on the sandwich?
The egg is on the sandwich.
    src        edge_attr  dst
0     0   to the left of    3
1     0   to the left of   10
2     1   to the left of    3
3     1               on    0
4     1   to the left of   10
5     2  to the right of    5
6     2  to the right of   10
7     2  to the right of    3
8     3               on    5
9     3  to the right of    0
10    3  to the right of    9
11    3  to the right of    1
12    3   to the left of    2
13    3  to the right of    4
14    4   to the left of   10
15    4               on    3
16    4   to the left of    3
17    5               on    7
18    5   to the left of    2
19    6  to the right of    7
20    7   to the left of   10
21    7   to the left of    6
22    7               on    8
23    7   to the left of   11
24    9   to the left of    3
25    9               on    7
26    9   to the left of   10
27   10  to the right of    7
28   10  to the right of    9
29   10   to the left of    2
30   10  to the right of    1
31   10  to the right of    0
32   10  to the right of    4
33   11  to the right of    7