public abstract class main6 {
    public static void main(String [] args) {
        StackI<Integer> s=new CompStack1<Integer>();
        s.push(2);  System.out.println("s="+s);
        s.push(3);  System.out.println("s="+s);
        s.push(1);  System.out.println("s="+s);
        s.push(9);  System.out.println("s="+s);
        s.pop();    System.out.println("s="+s);
        s.pop();    System.out.println("s="+s);
        s.push(9);  System.out.println("s="+s);
        s.push(1);  System.out.println("s="+s);
    }
}