diff --git a/book/chapter1/binary.hpp b/book/chapter1/binary.hpp
new file mode 100755
index 0000000..4c8b724
--- /dev/null
+++ b/book/chapter1/binary.hpp
@@ -0,0 +1,13 @@
+
+#include "boost/mpl/long.hpp"
+#include "boost/mpl/alias.hpp"
+
+template< long n > struct binary
+    : mpl::long_< ( binary< n / 10 >::value << 1 ) + n % 10 >
+{
+};
+
+template<> struct binary<0>
+    : mpl::long_<0>
+{
+};