# topo-sort a DAG specified by i -> j edge pairs
# https://en.wikipedia.org/wiki/File:Directed_acyclic_graph_2.svg
tsort < 3 8
> 3 10
> 5 11
> 7 8
> 7 11
> 8 9
> 11 2
> 11 9
> 11 10
> EOF