ceph/src/boost/libs/polygon/example/input_data/polygon/polygon_007.txt

   1 0
   2 12
   3 0 0 8 3
   4 8 3 10 13
   5 10 13 16 6
   6 16 6 16 15
   7 16 15 25 10
   8 25 10 15 1
   9 15 1 27 -1
  10 27 -1 14 -4
  11 14 -4 13 3
  12 13 3 11 -5
  13 11 -5 10 0
  14 10 0 0 0