import java.nio.charset.*;


class Test extends Thread {
  public static void main(String args[]) throws Throwable {
    int nofThreads = 2;
    if (args.length > 0) nofThreads = Integer.parseInt(args[0]);

    Thread[] threads = new Thread[nofThreads];
    for (int i = 0; i < threads.length; i++) {
      threads[i] = new Test();
      threads[i].start();
    }

    for (int i = 0; i < threads.length; i++) {
      threads[i].join();
    }

    System.out.println("OK");
  }

  public void run() {
    Charset.availableCharsets();
  }
}