#include <CGAL/Homogeneous.h>
#include <CGAL/Nef_polyhedron_3.h>
#include <CGAL/IO/Nef_polyhedron_iostream_3.h>
#include <cassert>
int main() {
Nef_polyhedron N;
std::cin >> N;
assert((N - N.boundary()) == N.interior());
assert(N.closure() == N.complement().interior().complement());
assert(N.regularization() == N.interior().closure());
return 0;
}