/in/foo.cc: In function 'bool is_26(std::__cxx11::string)':
/in/foo.cc:17:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < x.length(); i++)
                         ~~^~~~~~~~~~~~
/in/foo.cc: In function 'void Translate(std::__cxx11::string)':
/in/foo.cc:62:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < x.length(); i++)
                     ~~^~~~~~~~~~~~