#include <omp.h>
#include <stdio.h>
int main (int argc, char *argv[]) {
 int id, nthreads;
 #pragma omp parallel private(id)    #<-- variable “id” is private to each respective threads
 {
   id = omp_get_thread_num();
   printf("Hello World from thread %d\n", id);
   #pragma omp barrier
   if ( id == 0 ) {
     nthreads = omp_get_num_threads();
     printf("There are %d threads\n",nthreads);
   }
 }
 return 0;
}