#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
#include <CGAL/Nef_polyhedron_3.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/draw_nef_3.h>
#include <fstream>
#include <iostream>
int main(int argc, char *argv[])
{
Polyhedron P;
ifs >> P;
Nef_polyhedron N(P);
return EXIT_SUCCESS;
}