What's located on top of the pizza?
The sauce is on top of the pizza.
    src        edge_attr  dst
0     0   to the left of   10
1     0   to the left of    9
2     1             with   10
3     1             with    2
4     1             with    5
5     1             with    6
6     2               on    1
7     5        on top of    1
8     6               on    1
9     8   to the left of   11
10    9  to the right of    0
11   10               on    1
12   10  to the right of    0
13   11  to the right of    8