/in/foo.cc: In function 'void dfs_R(int)':
/in/foo.cc:36:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<redge[x].size(); i++)
                  ~^~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:52:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<edge[x].size(); i++)
                  ~^~~~~~~~~~~~~~~
/in/foo.cc: In function 'void solve()':
/in/foo.cc:91:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<temp[i].size(); j++)
                      ~^~~~~~~~~~~~~~~
/in/foo.cc: In function 'int Answer()':
/in/foo.cc:150:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0; i<root.size(); i++)
                      ~^~~~~~~~~~~~