Черга

Queue<String> queue = new LinkedList<>();

queue.offer("Lviv");

queue.offer("Kyiv");

queue.offer("Odesa");

queue.offer("Dnipro");

System.out.println(queue.peek());

System.out.println(queue.size());

String town;

while ((town = queue.poll()) != null) {

     System.out.println(town);

}

System.out.println(queue.size());