diff --git a/smallchat-server.c b/smallchat-server.c
index 5f4679e..91d68b3 100644
--- a/smallchat-server.c
+++ b/smallchat-server.c
@@ -43,7 +43,7 @@
  * =========================================================================== */
 
 #define MAX_CLIENTS 1000 // This is actually the higher file descriptor.
-#define SERVER_PORT 7711
+#define DEFAULT_SERVER_PORT 7711
 
 /* This structure represents a connected client. There is very little
  * info about it: the socket descriptor and the nick name, if set, otherwise
@@ -113,7 +113,7 @@ void freeClient(struct client *c) {
 }
 
 /* Allocate and init the global stuff. */
-void initChat(void) {
+void initChat(int server_port) {
     Chat = chatMalloc(sizeof(*Chat));
     memset(Chat,0,sizeof(*Chat));
     /* No clients at startup, of course. */
@@ -122,11 +122,12 @@ void initChat(void) {
 
     /* Create our listening socket, bound to the given port. This
      * is where our clients will connect. */
-    Chat->serversock = createTCPServer(SERVER_PORT);
+    Chat->serversock = createTCPServer(server_port);
     if (Chat->serversock == -1) {
         perror("Creating listening socket");
         exit(1);
     }
+    printf("smallchat server is run on port %d \n", server_port);
 }
 
 /* Send the specified string to all connected clients but the one
@@ -148,8 +149,9 @@ void sendMsgToAllClientsBut(int excluded, char *s, size_t len) {
  * 1. Accept new clients connections if any.
  * 2. Check if any client sent us some new message.
  * 3. Send the message to all the other clients. */
-int main(void) {
-    initChat();
+int main(int argc, char **argv) {
+    int server_port = argc == 2 ? atoi(argv[1]) : DEFAULT_SERVER_PORT;
+    initChat(server_port);
 
     while(1) {
         fd_set readfds;