What do you think is the color of the building in the center of the picture?
The tower is gray.
   src        edge_attr  dst
0    0  to the right of    7
1    1  to the right of   11
2    1  to the right of    7
3    4               in    2
4    6  to the right of   10
5    7   to the left of    0
6    7   to the left of    1
7   10   to the left of    6
8   11   to the left of    1