#include "iostream.h"

class X{ public: X(int i) {xi =i;xc = 'a';};
         X() {xi=0; xc= 'z';};
         int xi; char xc;};

class Y: public X{public:  Y(int i) {yi = i*i;};
                  Y(int i, int j):X(j) {yi =i*i;};
         int yi;};

main(){

Y y1(4);
cout<<y1.yi<<"  "<<y1.xi<<"  "<<y1.xc<<'\n';

Y y2(4,5);
cout<<y2.yi<<"  "<<y2.xi<<"  "<<y2.xc<<'\n';

y1 = y2;

cout<<y1.yi<<"  "<<y1.xi<<"  "<<y1.xc<<'\n';
}

// output 
// 16 0 z
// 16 5 a
// 16 5 a