--- demos/fifteen.cc.orig	Thu Dec 11 18:27:13 2003
+++ demos/fifteen.cc	Thu Dec 11 18:27:34 2003
@@ -20,6 +20,7 @@
 #include "fifteen.h"
 
 #include <stdio.h>
+#include <time.h>
 
 
 #define PIECE_SIZE 50