/in/foo.cc: In function 'void DFS(int)':
/in/foo.cc:43:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0,v;i<e[x].size();i++) 
                   ~^~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:101:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j=0;j<lv[x].size();j++)
                ~^~~~~~~~~~~~~