#include<iostream>
using namespace std;

class stack
{
	int data;
	stack* next;

	public:

	stack();
	int pop();
	void push(int);

};

stack::stack()
{
	data=0;
	next=NULL;
}

int stack::pop()
{
	if(next==NULL)
	{
		cout<<"Stack empty"<<endl;
		exit(0);
	}

	stack* p=this;

	while(p->next->next!=NULL)
		p=p->next;

	int temp=p->next->data;
	delete p->next;

	return temp;

}

void push(int a)
{
	stack* p=this;

	while(p->next!=NULL)
		p=p->next;

	p->next=new stack;
	p->next->data=a;

}