void DrawMass(TString nSt="") {

  TStopwatch timer;
  timer.Start();

//  gROOT->LoadMacro("$VMCWORKDIR/gconfig/basiclibs.C");
//  basiclibs();

TStyle *plain = new TStyle("Plain","Plain Style(no colors/fill areas)");
//plain->SetCanvasBorderMode(0);
//plain->SetPadBorderMode(0);
plain->SetPadColor(0);
plain->SetCanvasColor(0);
plain->SetTitleColor(0);
plain->SetStatColor(0);
plain->SetOptStat(110010);
plain->SetOptFit(0011);
plain->SetStatW(0.225);
plain->SetStatH(0.06);
//plain->SetStatX(0.7);
plain->SetOptTitle(0);
plain->cd();

  TString name = "out.root";
  TFile *dirOld = new TFile("out_old.root","read");
  TFile *dirNew = new TFile("out_new.root","read");

  TH1D *hResOld, *hResNew;
  TH1D *hPullOld, *hPullNew;
  TH1D *hMassOld, *hMassNew;
  TF1  *fResOld, *fResNew;
  TF1  *fPullOld, *fPullNew;
  TF1  *fMassOld, *fMassNew;
    
  hResOld = (TH1D*) dirOld->Get("resM");
  fResOld = new TF1("resFitOld","gaus");
  fResOld->SetLineColor(2);
  hResOld->Fit("resFitOld","","",hResOld->GetXaxis()->GetXmin(),hResOld->GetXaxis()->GetXmax());
    
  hPullOld = (TH1D*) dirOld->Get("pullM");
  fPullOld = new TF1("pullFitOld","gaus");
  fPullOld->SetLineColor(2);
  hPullOld->Fit("pullFitOld","","",hPullOld->GetXaxis()->GetXmin(),hPullOld->GetXaxis()->GetXmax());
  
  hMassOld = (TH1D*) dirOld->Get("massAll");
  hMassOld->SetLineColor(1);
  hMassOld->GetXaxis()->SetRangeUser(1.7, 2.0);
  fMassOld = new TF1("MassAllFitOld","gaus");
  fMassOld->SetLineColor(2);
  hMassOld->Fit("MassAllFitOld","","",1.7,2);

  hResNew = (TH1D*) dirNew->Get("resM");
  fResNew = new TF1("resFitNew","gaus");
  fResNew->SetLineColor(2);
  hResNew->Fit("resFitNew","","",hResNew->GetXaxis()->GetXmin(),hResNew->GetXaxis()->GetXmax());
    
  hPullNew = (TH1D*) dirNew->Get("pullM");
  fPullNew = new TF1("pullFitNew","gaus");
  fPullNew->SetLineColor(2);
  hPullNew->Fit("pullFitNew","","",hPullNew->GetXaxis()->GetXmin(),hPullNew->GetXaxis()->GetXmax());

  hMassNew = (TH1D*) dirNew->Get("massAll");
  hMassNew->SetLineColor(1);
  hMassNew->GetXaxis()->SetRangeUser(1.7, 2.0);
  fMassNew = new TF1("MassAllFitNew","gaus");
  fMassNew->SetLineColor(2);
  hMassNew->Fit("MassAllFitNew","","",1.7, 2.0);
  
  TCanvas *c1;
  c1 = new TCanvas("c1","position",0,0,1200,800);
//  c1 -> Divide(NParameters-2,2);
  c1 -> Divide(3,2);

  c1->UseCurrentStyle();

  c1->cd(1);
  hMassOld->GetXaxis()->SetTitle("Old Mass D^{0} [GeV/c^{2}]");
  hMassOld->GetXaxis()->SetTitleOffset(1);
  hMassOld->Draw();
  fMassOld->Draw("same");
  
  c1->cd(2);
  hResOld->GetXaxis()->SetTitle("Old Residual (M^{reco} - M^{mc}) [GeV/c^{2}]");
  hResOld->GetXaxis()->SetTitleOffset(1);
  hResOld->Draw();
  fResOld->Draw("same");

  c1->cd(3);
  hPullOld->GetXaxis()->SetTitle("Old Pull M");
  hPullOld->GetXaxis()->SetTitleOffset(1);
  hPullOld->Draw();
  fPullOld->Draw("same");

  c1->cd(4);
  hMassNew->GetXaxis()->SetTitle("New Mass D^{0} [GeV/c^{2}]");
  hMassNew->GetXaxis()->SetTitleOffset(1);
  hMassNew->Draw();
  fMassNew->Draw("same");

  c1->cd(5);
  hResNew->GetXaxis()->SetTitle("New Residual (M^{reco} - M^{mc}) [GeV/c^{2}]");
  hResNew->GetXaxis()->SetTitleOffset(1);
  hResNew->Draw();
  fResNew->Draw("same");
  
  c1->cd(6);
  hPullNew->GetXaxis()->SetTitle("New Pull M");
  hPullNew->GetXaxis()->SetTitleOffset(1);
  hPullNew->Draw();
  fPullNew->Draw("same");
 
  c1->SaveAs("MassComparison.pdf");
 
  timer.Stop();
  Double_t rtime = timer.RealTime();
  Double_t ctime = timer.CpuTime();
  printf("RealTime=%f seconds, CpuTime=%f seconds\n",rtime,ctime);

}