// multiple inheritance
#include <iostream.h>

class CPolygon {
protected:
    int width, height;
public:
    void set_values (int a, int b)
    { width=a; height=b;}
};

class COutput {
public:
    void output (int i);
};

void COutput::output (int i) {
  cout << i << endl;
}

class CRectangle: public CPolygon, public COutput {
public:
    int area (void)
    { return (width * height); }
};

class CTriangle: public CPolygon, public COutput {
public:
    int area (void)
    { return (width * height / 2); }
};
  
int main () {
  CRectangle rect;
  CTriangle trgl;
  rect.set_values (4,5);
  trgl.set_values (4,5);
  rect.output (rect.area());
  trgl.output (trgl.area());
  return 0;
}