diff --git a/dn3/Makefile b/dn3/Makefile
new file mode 100644
index 0000000..3cc18b1
--- /dev/null
+++ b/dn3/Makefile
@@ -0,0 +1,18 @@
+CC=gcc
+CFLAGS=-g -Wall -lpthread -fopenmp -lm
+DESTINATION=/ceph/grid/home/gs0104/dn/dn3
+
+all: server
+
+server: server.c
+	$(CC) $(CFLAGS) server.c -o server
+
+clean: 
+	rm server
+
+push:
+	 rsync -a --progress . nsc:$(DESTINATION)
+
+run_remote:
+	 ssh nsc 'cd $(DESTINATION); make clean; make server;'	
+	 ssh nsc 'srun --reservation=fri --ntasks=1 --cpus-per-task=8 --nodes=1 $(DESTINATION)/server'
diff --git a/dn3/server b/dn3/server
new file mode 100755
index 0000000..1824eef
Binary files /dev/null and b/dn3/server differ
diff --git a/dn3/server.c b/dn3/server.c
new file mode 100644
index 0000000..e9ef89a
--- /dev/null
+++ b/dn3/server.c
@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <pthread.h> 
+#include <omp.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <math.h>
+
+#define N_THREADS 8
+#define N_DIMENSIONS 200000000
+
+pthread_barrier_t b;
+long *p_s;
+long *q_s;
+double res[N_THREADS];
+int active_threads[N_THREADS];
+
+void setup() {
+  p_s = (long *) malloc(N_DIMENSIONS * sizeof(long));
+  q_s = (long *) malloc(N_DIMENSIONS * sizeof(long));
+  for (long i = 0; i < N_DIMENSIONS; i++) {
+    p_s[i] = rand() % 10;
+    q_s[i] = rand() % 10;
+  }
+}
+
+void *calculate(void* arg) {
+  int *myrank = (int *)arg;
+  long mystart = (long)(N_DIMENSIONS/ (double)N_THREADS * *myrank);
+  long myend = (long)(N_DIMENSIONS / (double)N_THREADS * (*myrank + 1));
+  double sum = 0;
+
+
+  for (long i = mystart; i < myend; i++) {
+    sum +=  pow(p_s[i] - q_s[i], 2);
+  }
+
+  res[*myrank] = sum;
+  printf("Thread2 %d finished\n", *myrank);
+  fflush(stdout);
+  pthread_barrier_wait( &b );
+
+  int n_threads = N_THREADS;
+
+  if (n_threads != 1) {
+
+    n_threads = N_THREADS / 2;
+    if (*myrank >= n_threads) {
+      active_threads[*myrank] = -1;
+    }
+  }
+
+  while(1) {
+    if(active_threads[*myrank] != -1) {
+      res[*myrank] = res[*myrank * 2] + res[*myrank *2 + 1];
+    }
+    pthread_barrier_wait( &b );
+
+    n_threads = n_threads / 2;
+    if (n_threads == 1 || n_threads == 0) {
+      break;
+    }
+    if (*myrank >= n_threads) {
+      //printf("Thread %d is on pause\n", *myrank);
+      active_threads[*myrank] = -1;
+    }
+    pthread_barrier_wait( &b );
+  }
+  
+  return NULL;
+}
+
+
+int main() {
+  pthread_t t[N_THREADS];
+  setup();
+  double dt = omp_get_wtime(); // start timing
+  int p[N_THREADS];
+
+  if(N_THREADS %2 != 0 && N_THREADS >= 2) {
+    printf("Number of threads must be even!\n");
+    return 1;
+  }
+  pthread_barrier_init( &b, NULL, N_THREADS );
+
+  for(int i = 0; i < N_THREADS; i++ ) {
+    p[i] = i;
+    pthread_create(&t[i], NULL, calculate, (void *)&p[i]);
+  }
+
+  for(int i=0; i<N_THREADS; i++)
+      pthread_join(t[i], NULL);
+
+  dt = omp_get_wtime() - dt; // finish timing
+ 
+  printf("Execution time: %lf, caluclation result: %lf ", dt, sqrt(res[0]));
+  return 0;
+
+  // 8 THREADS: Execution time: 0.807376, caluclation result: 49748.358094
+  // 4 THREADS: Execution time: 1.614672, caluclation result: 49748.358094
+  // 2 THREADS: Execution time: 3.223820, caluclation result: 57445.749660
+  // 1 THREADS: Execution time: 4.698835, caluclation result: 57445.749660 
+}