/in/foo.cc: In function 'int judge(std::__cxx11::string)':
/in/foo.cc:13:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size()/2;i++)
              ~^~~~~~~~~~~
/in/foo.cc: In function 'long long int stringtoint(std::__cxx11::string)':
/in/foo.cc:25:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size();i++)
              ~^~~~~~~~~