What color are the letters?
The letters are red.
   src        edge_attr  dst
0    0   to the left of   10
1    0   to the left of   11
2    3   to the left of   10
3    6  to the right of   12
4   10  to the right of    3
5   10  to the right of    0
6   10  to the right of   11
7   11  to the right of    0
8   11   to the left of   10
9   12   to the left of    6