#include <iostream>
#include <boost/chrono.hpp>
using namespace std;
int main () {
for (int i=0; i<10; i++) {
    boost::chrono::high_resolution_clock::time_point start=
    boost::chrono::high_resolution_clock::now();
    for (int i=0; i<10; i++) {
      cout<<"HELLO" << "\n";
      }
      sleep(0.5);
      boost::chrono::high_resolution_clock::time_point stop=
      boost::chrono::high_resolution_clock::now();
      boost::chrono::microseconds ms=
      boost::chrono::duration_cast<boost::chrono::microseconds>(stop-start);
      cout<< " time (us)=" <<ms.count()<<endl;
      return 0;
      }
      }