import java.util.*;

class Main {
  static Deque queue;
  static ArrayQueue concurrentQueue;
  static List[] deqValues;
  static int TH = 10, NUM = 1000;

  // Each unsafe thread enqs N numbers and deqs N, adding
  // them to its own deqValues for checking; using Java's
  // sequential queue implementation, ArrayDeque.
  static Thread unsafe(int id, int x, int N) {
    return new Thread(() -> {
      String action = "enq";
      try {
      for (int i=0, y=x; i