#include<iostream>
using namespace std;
class A{
    public:
    A(){
        cout<<"A\n";
    }
    
};
class B: public A{
    public:
    B(){
        cout<<"B\n";
    }
    
};
class C: public B{
    public:
    C(){
        cout<<"C\n";
    }
    
};

class D: public A, public B{
    public:
    D(){
        cout<<"D\n";
    }
    
};

class E{
    public:
    E(){
        cout<<"E\n";
    }
    
};

class F: public C, public D, public E{
    public:
    F(){
        cout<<"F\n";
    }
    
};

int main(){
    F f;
    return 0;
}