#include <CGAL/Homogeneous.h>
#include <CGAL/Nef_polyhedron_3.h>
#include <CGAL/IO/Nef_polyhedron_iostream_3.h>
int main() {
typedef Nef_polyhedron_3::Vertex_const_iterator Vertex_const_iterator;
typedef Nef_polyhedron_3::Nef_polyhedron_S2 Nef_polyhedron_S2;
Nef_polyhedron_3 N;
std::cin >> N;
Vertex_const_iterator v = N.vertices_begin();
Nef_polyhedron_S2 S(N.get_sphere_map(v));
int i=0;
SFace_const_iterator sf;
for(sf = S.sfaces_begin(); sf != S.sfaces_end(); sf++) {
SFace_cycle_const_iterator it;
std::cout << "the sface cycles of sface " << i++ << " start with an\n";
for(it = sf->sface_cycles_begin(); it != sf->sface_cycles_end(); it++) {
if (it.is_svertex())
std::cout << " svertex at position "
else if (it.is_shalfedge())
std::cout << " shalfedge from "
else if (it.is_shalfloop())
std::cout << " shalfloop lying in the plane "
}
}
return 0;
}