fix cpp
diff --git a/examples/cpp/route_guide/helper.cc b/examples/cpp/route_guide/helper.cc
index c2415af..f76990f 100644
--- a/examples/cpp/route_guide/helper.cc
+++ b/examples/cpp/route_guide/helper.cc
@@ -40,7 +40,7 @@
 #include <vector>
 #include "route_guide.grpc.pb.h"
 
-namespace examples {
+namespace routeguide {
 
 std::string GetDbFileContent(int argc, char** argv) {
   std::string db_path;
@@ -174,5 +174,5 @@
 }
 
 
-}  // namespace examples
+}  // namespace routeguide