/in/foo.cc: In function 'int main()':
/in/foo.cc:20:54: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |                                         for(int i=0;i<g[y].size();i++)
      |                                                     ~^~~~~~~~~~~~