/in/foo.cc: In function 'int main()':
/in/foo.cc:18:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |         for(int i=2;i<=s.size();i++)
      |                     ~^~~~~~~~~~
/in/foo.cc:20:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |                 for(int l=0,r=l+i-1;r<s.size();l++,r++)
      |                                     ~^~~~~~~~~