Which color is the mat which is to the left of the vegetable?
The mat is black.
    src        edge_attr  dst
0     0               on    3
1     0   to the left of    1
2     1  to the right of    5
3     1  to the right of    6
4     1  to the right of    0
5     2  to the right of    4
6     3               on    6
7     4  to the right of    6
8     4   to the left of    2
9     5   to the left of    1
10    5  to the right of    6
11    6   to the left of    1
12    6   to the left of    4
13    6   to the left of    5