Exercise of STL stack

#include <iostream>
#include <stack>

using namespace std;

int main()
{
    cout << "STL stack exercise" << endl << endl;

    stack<int> MyStack;
    cout << "init without anything" << endl;
    cout <<"MyStack.size(): " << MyStack.size() << endl << endl;

    cout << "push something in" << endl;
    MyStack.push(1);
    MyStack.push(2);
    MyStack.push(3);
    MyStack.push(4);
    cout <<"MyStack.size(): " << MyStack.size() << endl << endl;

    cout << "pop all out" << endl;
    while (!MyStack.empty())
    {
        cout << MyStack.top() << endl;
        MyStack.pop();
    }

    cout << endl << endl;

    return 0;
}