{
  gROOT->Reset();
  
  // Draw histos filled by Geant4 simulation 
  //   
  TFile f = TFile("AnaEx01.root");  
  TCanvas* c1 = new TCanvas("c1", "  ");
  
  TDirectory* dir = f.Get("histo");
    
  TH1D* hist1 = (TH1D*)dir->Get("1");      
  hist1->Draw("HIST");
  
  TH1D* hist2 = (TH1D*)dir->Get("2");      
  hist2->Draw("HIST");
  
  TH1D* hist3 = (TH1D*)dir->Get("3");    
  hist3->Draw("HIST");
  
  TH1D* hist4 = (TH1D*)dir->Get("4");      
  hist4->Draw("HIST");          
}