/in/foo.cc: In function 'int main()':
/in/foo.cc:61:69: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   61 |                     if(id[to] && id[to]!=cnt && V[id[to]].size()+num<=B && (!best || V[best].size()>V[id[to]].size()))
      |                                                 ~~~~~~~~~~~~~~~~~~~~^~~