public class Stack implements Cloneable {
	
	private Object [] array;
	private int capacity;
	private int size;
	
	public Stack() {
		array = new Object[10];
		capacity = 10;
		size = 0;
	}
	
	public Stack(int capacity) {
		this.capacity = capacity/10*10 + 10;
		array = new Object[this.capacity];	
		size = 0;
	}
	
	public Object push(Object item) {
		Object temp [] = null;
		if(size == capacity) {
			capacity += 10;
			temp = new Object[capacity];
			for(int i=0; i<size; i++)
				temp[i] = array[i];
			array = temp;			
		}
		array[size++] = item;
		return array[size-1];
	}
	
	public Object pop() throws EmptyStackException {
		if(size == 0)
			throw new EmptyStackException();
		return array[--size];
	}
	
	public Object peek() throws EmptyStackException {
		if(size == 0)
			throw new EmptyStackException();
		return array[size-1];
	}
	
	public boolean empty() {
		return size == 0;
	}
	
	public int size() {
		return size;
	}
	
	public Object clone() throws CloneNotSupportedException {
		Stack result =  (Stack)super.clone();
		result.array =  array.clone();
		return result;
	}
}