#include <iostream>
using namespace std;
class Base {
    private:
    char c;

    public:
    Base(char n): c(n) {}
    virtual ~Base() {
        cout << c;
    }
};

class Der:public Base {
    private:
    char c;
    public:
    Der(char n):Base(n + 1), c(n) {}
    ~Der(){
        cout << c;
    }
};

int main() {
    Der('X');
    return 0;
}

/*
XY
*/