C++ two headers with same namespace

Question

I have two header files named aaa.hpp and bbb.hpp,
i have namespace named sameName in the both files (aaa.hpp and bbb.hpp)
if i run my code, the compiler give an error...
please see this code: https://code.sololearn.com/ca1a6A12A92a/#cpp
Question: how to specify which namespace is used?
sorry for bad english, thanks.

Answer 1

To run this in Code Playground:
Comment out the #include directives for "aaa.hpp" and "bbb.hpp" , then #include <iostream>.
Move the lines from aaa.hpp and bbb.hpp above main. This is just like how it's done by #include, all the definitions of the included headers are sort of "added" to the beginning of .cpp content.
Can't have 2 function definitions (with same name) under one namespace. Rename one of them.
Call `std::cout` rather than just `cout`