#include <iostream>
    using namespace std;
    class Polygon
    {
        protected:
        int W, H;
        public:
        void set_values(int width, int height)
        {
            W = width; H = height;
        }
    };
    class Coutput
    {
        public:
        void output(int i);
    };
    void Coutput::output(int i)
    {
        cout << i <<" ";
    }
    class Rectangle:public Polygon, public Coutput
    {
        public:
        int area()
        {
            return(W * H);
        }
    };
    class Triangle:public Polygon, public Coutput
    {
        public:
        int area()
        {
            return(W * H / 2);
        }
    };
    int main()
    {
        Rectangle Rect;
        Triangle trgl;
        Rect.set_values(5, 2);
        trgl.set_values(5, 2);
        Rect.output(Rect.area());
        trgl.output(trgl.area());
        return 0;
    }