compila ?
import java.util.Stack;
public class Building {
private final static Integer floor1 = new Integer(1);
private final static Integer floor2 = new Integer(2);
private final static Integer floor3 = new Integer(3);
public static void main(String[] args) {
Stack building = new Stack();
building.push(floor1);
building.push(floor2);
building.push(floor3);
for (int i = 0; i < building.size();i++)
building.peek();
System.out.println (building.pop());
}
}