#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#define THREADS 10
static int sum = 1;
void *updater(void *ptr){
    sum = sum + 1; 
    pthread_exit(NULL);
}
int main(void){
  int i;
  pthread_t threads[THREADS];
  for(i = 0; i < THREADS ; i++)
    pthread_create(&threads[i],NULL,updater,NULL);
  for(i = 0; i < THREADS ; i++)
    pthread_join(threads[i],NULL);
  fprintf(stderr, "sum = %d\n", sum);
  exit(EXIT_SUCCESS);
}