/in/foo.cc: In function 'int main()':
/in/foo.cc:13:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |         for (int i = 0; i < s.length(); i++)
      |                         ~~^~~~~~~~~~~~
/in/foo.cc:12:13: warning: unused variable 'cnt' [-Wunused-variable]
   12 |         int cnt = 0;
      |             ^~~