/in/foo.cc: In function 'int main()':
/in/foo.cc:36:14: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::priority_queue<int>::size_type' {aka 'long unsigned int'} [-Wformat=]
   36 |     printf("%d\n", q.size());
      |             ~^     ~~~~~~~~
      |              |           |
      |              int         std::priority_queue<int>::size_type {aka long unsigned int}
      |             %ld