#include <omp.h>
#include <stdio.h>
#include <stdlib.h>

int main() {
   #pragma omp parallel num_threads(2)
   {
      #pragma omp single
      // Only a single thread can read the input.
      printf("read input TID= %d\n", omp_get_thread_num());

      // Multiple threads in the team compute the results.
      printf("compute results\n");

      #pragma omp single
      // Only a single thread can write the output.
      printf("write output TID= %d\n", omp_get_thread_num());
    }
}