/in/foo.cc: In function 'int toint(std::__cxx11::string)':
/in/foo.cc:12:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0;i<s.length();i++)
                  ~^~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:79:13: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
     cout << ans << endl;
             ^~~