public interface StoreFunc {
void addBuyers (int ab);
void ejectBuyers (int eb);
void setState (int s);
void show();}

class Cashier {
String badge;
int state;
Cashier (String bd) {
badge = bd;
state = 0; }}

class Store implements StoreFunc {
String address,
int openingHours;
int state;
static int maxProfit;
Cashier c;
Bus (String ad, int oh, String bd) {
address = ad;
openingHours = oh;
state = 1;
c = new Cashier (bd);}
public void addBuyers (int ab) {
try {
if (state != 1) throws IllegalArgumentException exc;
if (c.state == 0) throws IndexOutOfBoundException exc;}
static void setMaxProfit (int maxProfit){
…}}

class Products {
String farm;
String shelfLife;
Products (String f, String sl){
farm = f;
shelfLife = sl;
void setFarm(String farm){…}
void setShelfLife(String shelfLife){…}

class ProductStore extends Store {
Products prod;
ProductStore (String ad, int oh, String bd, String f, String sl){
super (ad, oh, bd);
prod = new Products (f, sl);}
void show() {…}}

public class Main{
public static void main (String[] args){
Store store = new Store(…);
store.addBuyers (10);
store.c.changeState(1);
store.addBuyers(10);
ProductStore pStore = new ProductStore (…);
StoreFunc store1;
store1 = store;
store1.show();
store1 = pStore;
store1.show();
…}