/in/foo.cc: In function 'int main()':
/in/foo.cc:9:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |         for (int i=0;i<=s.size()-1;i++)
      |                      ~^~~~~~~~~~~~
/in/foo.cc:11:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |                 if (i==s.size()-1) cout<<res;
      |                     ~^~~~~~~~~~~~