import java.awt.*;
import java.awt.event.*;

class MyStack
{
	public int size=20;
	private int s[] = new int[size];
	private int top=0;
	public static void MyStack ()
	{
		
	}
	public void Push (int x)
	{
		if (top<size)
		{
			s[top]=x;	
			top++;
			System.out.println("Top: " +top);
		}
		else
			System.out.println("Error 1: Stack overflow.");
			
	}
	public int Pop ()
	{
		return (s[--top]);	
	}

}