boost/libs/polygon/example/input_data/polygon/polygon_012.txt

0
12
0 0 100 0
100 0 100 100
100 100 0 100
0 100 0 0
15 15 60 20
60 20 87 23
60 20 57 47
15 85 30 80
30 80 25 65
30 80 60 70
60 70 75 65
60 70 65 85