/in/foo.cc: In function 'int main()':
/in/foo.cc:20:30: warning: comparison of integer expressions of different signedness: 'std::priority_queue<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   20 |                 if (pq.size()>=k&&!ok) ok=1,maxx=pq.top();
      |                     ~~~~~~~~~^~~