#include <iostream>
#include <cmath>

using namespace std;

const float PI = 3.14;

class DuongTron
{
private:
	int x, y;
	float r;
public:
	DuongTron();
	DuongTron(int toaDoX, int toaDoY, float banKinh);
	void nhap();
	void xuat();
	double dienTich();
	double chuVi();
	~DuongTron();
};

DuongTron::DuongTron() : x(0), y(0), r(1) {}

DuongTron::DuongTron(int toaDoX, int toaDoY, float banKinh) 
	: x(toaDoX), y(toaDoY), r(banKinh) {}

void DuongTron::nhap()
{
	cout << "Nhap toa do x: "; 
	cin >> x;
	cout << "Nhap toa do y: ";
	cin >> y;
	cout << "Nhap ban kinh r: ";
	cin >> r;
}

void DuongTron::xuat()
{
	cout << "Chu vi: " << chuVi() << endl;
	cout << "Dien tich: " << dienTich() << endl;
}

double DuongTron::dienTich()
{
	return PI * r * r;
}

double DuongTron::chuVi()
{
	return 2 * PI * r;
}

DuongTron::~DuongTron()
{

}

int main()
{
	DuongTron a;
	a.nhap();
	a.xuat();

	return 0;
}