Which kind of vegetable is on the pizza?
The vegetables are onions.
    src        edge_attr  dst
0     0  to the right of    8
1     1        on top of    5
2     1  to the right of   12
3     1               on    5
4     1   to the left of   10
5     2  to the right of    4
6     2  to the right of    3
7     3   to the left of    2
8     3   to the left of   11
9     4   to the left of    2
10    5             with    1
11    5             with    7
12    5             with   12
13    5             with   11
14    5        on top of    4
15    5       covered in    1
16    7               on    5
17    7   to the left of    8
18    8   to the left of    0
19    8  to the right of    7
20   10  to the right of   12
21   10  to the right of    1
22   11               on    5
23   11  to the right of    3
24   12   to the left of   10
25   12   to the left of    1
26   12               on    5