Implement CLI application by editing main.cpp.
You may add new files to keep your code clean, if it is allowed in your challenge.

You can get arguments with ordinary C++ way, using int argc and char * argv[].

int main(int argc, char * argv[])
{
  // code to run
  return 0;
}

You can use cout, printf, etc.

  cout << argv[0] << endl

To compile, we are using clang g++ command.

If you want to change compile option or etc, please edit makefile.