/in/foo.cc: In function 'int main()':
/in/foo.cc:25:27: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   25 |         for (int j = 0; j <= strlen(b) - 1; j++) {
      |                         ~~^~~~~~~~~~~~~~~~