/**
* @author AlbertDarren
* @contact 2563491540@qq.com
*/
#include <iostream>
#include <stack>
#include <vector>
#include <list>
#include <deque>
using namespace std;

int main_7()
{
    stack<int,deque<int>> s;
    s.push(2);
    s.push(1);
    stack<int,vector<int>> s1;
    s1.push(1);
    s1.push(4);
    s1.push(-1);
    stack<int,list<int>> s2;
    s2.push(3);
    cout << s1.top() << endl;
    if (s.empty())
    {
        cout << "empty" << endl;
    }
    else
    {
        cout << "Not empty" << endl;
        cout << s.top() << endl;
        s.pop();
        cout << s.top() << endl;
        cout << s.size() << endl;
    }
	return 0;
}