/in/foo.cc: In function 'int main()':
/in/foo.cc:17:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |   for (int i = 2; i < m.length(); ++i)
      |                   ~~^~~~~~~~~~~~
/in/foo.cc:13:7: warning: unused variable 't' [-Wunused-variable]
   13 |   int t;
      |       ^