/in/foo.cc: In function 'void topo()':
/in/foo.cc:14:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |             for(int i=0;i<g[u].size();i++)
      |                         ~^~~~~~~~~~~~
/in/foo.cc:22:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         for(int i=0;i<g[u].size();i++)
      |                     ~^~~~~~~~~~~~