/in/foo.cc: In function 'int main()':
/in/foo.cc:27:46: warning: comparison of integer expressions of different signedness: 'int' and 'const long unsigned int' [-Wsign-compare]
   27 |                                 for(int k=0;k<min(n[i].a.size(),n[j].a.size());k++){
      |                                             ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~