public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); List<Integer> list = new LinkedList<>(); int counter = 0; for (int i = 0; i < 10; i++) { list.add(Integer.parseInt(reader.readLine())); } Iterator<Integer> iterator = list.iterator(); for (int i = 0; i < list.size(); i++) { while (iterator.hasNext()) { if (list.get(i).equals(iterator.next())) { counter++; } else { i++; } } } System.out.println(counter); }