Implement Stack in Java.
public class MyStack<E> { private static class Node<E> { E value; Node<E> next; public Node(E v, Node<E> n){ value = v; next = n; } } private Node<E> head; private int size = 0; public void push(E e) { head = new Node<E>(e, head); size++; } public E pop() throws Exception { if(size == 0) throw new Exception("Empty Stack!"); E e = head.value; head = head.next; size--; return e; } public E peek() throws Exception { if(size == 0) throw new Exception("Empty Stack!"); return head.value; } public int size() { return size; } }