Which kind of clothing is gray?
The clothing is a uniform.
   src        edge_attr  dst
0    0   to the left of    3
1    0   to the left of    1
2    1  to the right of    2
3    1  to the right of    0
4    2   to the left of    1
5    2   to the left of    3
6    3  to the right of    2
7    3  to the right of    0