text: #include<iostream>
  #include<thread>
  #include<mutex>
  
  std::mutex mtx;
  
  
  void printOneToTen() {
      std::thread::id th_id = std::this_thread::get_id();
      std::lock_guard<std::mutex> lck(mtx);
      std::cout << "Entering Thread: " << std::hex << th_id << std::endl;
      for (int i=1; i <= 10; i++) {
          std::cout << i << ",";
      }
      std::cout << std::endl;
  }
  
  
  int main() {
      auto th1 = std::thread(printOneToTen);
      auto th2 = std::thread(printOneToTen);
  
      th1.join();
      th2.join();
  
      return 0;
  }
  