c This is a sample maxflow problem
c from Lawler's "Combinatorial Optimization" book,
c page 111
c
c problem line
p 6 9
c source
n 1 s
c sink
n 2 t
c arc descriptors
a 1 2 3
a 1 3 2
a 2 4 2
a 3 2 1
a 3 5 2
a 4 3 1
a 4 6 3
a 5 4 1
a 5 6 2