/in/foo.cc:4:0: warning: ignoring #pragma warning  [-Wunknown-pragmas]
 #pragma warning(disable:4996)
 
/in/foo.cc: In function 'void dfs(std::__cxx11::string)':
/in/foo.cc:72:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < s.size(); i++)
                  ~~^~~~~~~~~~