What is the corn on?
The corn is on the sandwich.
    src        edge_attr  dst
0     1               on    4
1     1   to the left of    6
2     1   to the left of    3
3     3  to the right of    1
4     3     covered with    6
5     4             with   10
6     4               on   11
7     4             with    1
8     6  to the right of    1
9     8   to the left of   11
10    9          holding    4
11   10               on    4
12   11  to the right of    8