void getMaxRun(TString rootfile){

  //  TString rootfile  = "data44_dskim_evtstore.root";
  TString tree_ntp  = "dnt";

  TChain  *ch_ntp = new TChain(tree_ntp); 
  ch_ntp->Add(rootfile);

  Int_t run ; 

  ch_ntp->SetBranchAddress("run", &run);

  ch_ntp->GetEntry(ch_ntp->GetEntries()-1);

  cout << "Max Run: " << run << endl;

}