What food is not silver?
The food is a pepper.
    src        edge_attr  dst
0     0  to the right of    9
1     1  to the right of    8
2     2  to the right of   11
3     3               on    5
4     3   to the left of   11
5     5   to the left of   11
6     6               on   14
7     6  to the right of    8
8     7  to the right of   11
9     8               on   14
10    8   to the left of    6
11    8   to the left of    1
12    9   to the left of    0
13   11  to the right of    3
14   11   to the left of    2
15   11  to the right of    5
16   11   to the left of    7
17   14               on   12
18   14               on    4