#include <iostream>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_2.h>
#include <CGAL/Polyline_simplification_2/simplify.h>
namespace PS = CGAL::Polyline_simplification_2;
typedef PS::Stop_below_count_ratio_threshold Stop;
typedef PS::Squared_distance_cost Cost;
int main()
{
Polygon_2 polygon;
std::cin >> polygon;
Cost cost;
std::cout.precision(12);
std::cout << polygon << std::endl;
return 0;
}