#include <iostream>
using namespace std;


template <class x> class Node{
public:
	x	data;
	Node<x>	*next;
};


template <class x> class Stack{
public:
	Stack();
	~Stack();
	int	StackIsEmpty();
	int	StackIsFull();
	void	Push(x e);
	void	Pop(x &e);
	void	Error();

	Node<x>*	MakeNode(x e);
private:
	Node<x> *top;
};


int main(){
	Stack<int> s;
	s.Push(2);
	s.Push(4);
	s.Push(6);
	s.Push(8);

	int i;
	s.Pop(i);
	cout << i << endl;
	s.Pop(i);
	cout << i << endl;
	return 0;
}

template <class x> Stack<x>::Stack(){
	top = NULL;
}

template <class x> Stack<x>::~Stack(){
	x e;
	while(!StackIsEmpty()){
		Pop(e);
	}
}

template <class x> int Stack<x>::StackIsEmpty(){
	if (top == NULL)
		return 1;
	return 0;
}

template <class x> int Stack<x>::StackIsFull(){
	return 0;
}

template <class x> void Stack<x>::Push(x e){
	Node<x> *q = MakeNode(e);
	q->next = top;
	top = q;
}

template <class x> void Stack<x>::Pop(x &e){
	Node<x>	*q;
	if (StackIsEmpty()){
		Error();
	}
	else{
		e = top->data;
		q = top;
		top = top->next;
		delete q;
	}
}

template <class x> Node<x>* Stack<x>::MakeNode(x e){
	Node<x> *q = new Node<x>;
	q->data = e;
	q->next = NULL;
	return q;
}

template <class x> void Stack<x>::Error(){
	cout << "Error!!\n";
}