/in/foo.cc: In function 'int main()':
/in/foo.cc:79:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |       for (int row1 = 0; row1 + 1 < rowc.size(); row1++) {
      |                          ~~~~~~~~~^~~~~~~~~~~~~
/in/foo.cc:89:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |         for (int row1 = 0; row1 < rowc.size(); row1++) {
      |                            ~~~~~^~~~~~~~~~~~~