/in/foo.cc: In function 'int main()':
/in/foo.cc:103:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |     for (int i = 0; i < rows[0].cell.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:111:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |         for (int i = 0; i < r.cell.size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~