/in/foo.cc: In function 'int dfs(int, int)':
/in/foo.cc:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<outt[now].size();i++)
               ~^~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int work()':
/in/foo.cc:75:26: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=]
  printf("%d\n",ans.size());
                          ^
/in/foo.cc:76:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<ans.size();i++) printf("%d\n",ans[i]);
               ~^~~~~~~~~~~