--- Ex.14.java	2007-05-29 20:19:01.000000000 +0100
+++ Ex.15.java	2007-05-29 20:19:20.000000000 +0100
@@ -34,6 +34,6 @@
     int pc = 1;
     for (i = 0; i < pubs.length; ++i) if (r[i] != 0) ++pc;
     //@ assert pc > 0;
-    return pubs.length == 0? 0 : s / pubs.length;
+    return s / pc;
   }
 }