#include <stdio.h>
#include <pthread.h>
pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
int var = 0;


void* child_fn ( void* arg ) {
   int i,sum;
   pthread_mutex_lock(&mut);
   for(i=0;i<100000000;i++) sum=(sum+i*i) %1024;
   pthread_mutex_unlock(&mut);
   return NULL;
}

int main ( void ) {
   int i,sum;
   pthread_t child;
   pthread_create(&child, NULL, child_fn, NULL);
   pthread_mutex_lock(&mut);
   for(i=0;i<1000000000;i++) sum=(sum+i*i) % 1024;
   pthread_mutex_unlock(&mut);
   pthread_join(child, NULL);
   printf("%d\n", sum);
   return 0;
}