/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:19:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<G[u].size(); i++){
                  ~^~~~~~~~~~~~
/in/foo.cc: In function 'int d(int)':
/in/foo.cc:54:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<Map[x].size(); i++){
                  ~^~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:86:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(int i=0; i<G[u].size(); i++){
                          ~^~~~~~~~~~~~