due March 22

1.  Solve problems 2,3,4 of notes on planar graphs.

2.  Solve problem 29 of Ch 7 or KT.

Please do read Ch 7 of KT except for 7.3,7.4,7.13.  Most of it is
various applications (several covered in class) of maxflow-mincut.
The chapter is well written and you should see the many, many contexts
in which flow/cut ideas can be used.