/in/foo.cc: In function 'void dfs1(int, int)':
/in/foo.cc:64:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<v1[u].size();i++) buc[deg[v1[u][i]]+N]--;
               ~^~~~~~~~~~~~~
/in/foo.cc: In function 'void dfs2(int, int)':
/in/foo.cc:74:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<v3[u].size();i++) buc[v3[u][i]+N]++;
               ~^~~~~~~~~~~~~
/in/foo.cc:76:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<v2[u].size();i++) buc[v2[u][i]+N]--;
               ~^~~~~~~~~~~~~