{
  // Take care of hstackA
  //------------------------

  TH1F* histoA1 = new TH1F("histoA1", "", 40, -5, 5);
  TH1F* histoA2 = new TH1F("histoA2", "", 40, -5, 5);

  // Fill histos A with gaussians centered at 0
  histoA1->FillRandom("gaus", 1000);
  histoA2->FillRandom("gaus", 2000);

  colorNPB  = TColor::GetColor("#0000ff");
  colorPB = TColor::GetColor("#e60077");
  
  histoA1->SetLineColor(colorNPB);
  histoA1->SetFillStyle(4050);
  histoA1->SetFillColor(colorNPB);
  histoA1->SetLineWidth(2);
  
  histoA2->SetLineColor(colorPB);
  histoA2->SetFillStyle(4050);
  histoA2->SetFillColor(colorPB);
  histoA2->SetLineWidth(2);



  THStack* hstackA = new THStack("hstackA", "");

  hstackA->Add(histoA1);
  hstackA->Add(histoA2);


  // Take care of hstackB
  //-------------------------

  TH1F* histoB1 = new TH1F("histoB1", "", 40, -5, 5);
  TH1F* histoB2 = new TH1F("histoB2", "", 40, -5, 5);

  // Creating an offset gaussian distribution
  TF1 *myfunc= new TF1("myfunc", "gaus", 0, 3);
  myfunc->SetParameters(10.,1.5, 1);

  // Fill histos B with gaussians centered at 1.5
  histoB1->FillRandom("myfunc", 1500);
  histoB2->FillRandom("myfunc", 2000);

  colorNP1p = TColor::GetColor("#ee7700");
  colorP1p = TColor::GetColor("#0033cc");
  
  histoB1->SetLineColor(colorP1p);
  histoB1->SetFillStyle(4050);
  histoB1->SetFillColor(colorP1p);
  histoB1->SetLineWidth(2);
  
  histoB2->SetLineColor(colorNP1p);
  histoB2->SetFillStyle(4050);
  histoB2->SetFillColor(colorNP1p);
  histoB2->SetLineWidth(2);


  
  THStack* hstackB = new THStack("hstackB", "");

  hstackB->Add(histoB1);
  hstackB->Add(histoB2);



  // Set y range
  float Amax = hstackA->GetMaximum();
  float Bmax   = hstackB->GetMaximum();
  
  float yaxismax = TMath::Max(Amax, Bmax);
  
  hstackA->SetMaximum(yaxismax);
  hstackB->SetMaximum(yaxismax);



  // Draw the histograms
  //-----------------------


  TCanvas *c = new TCanvas;
  c->SetFrameFillColor(0);
  c->SetFrameFillStyle(4000);

  TColor *c1000 = new TColor(1000,0.,0.,0,"c1000",0.0);

  hstackA->Draw();
  hstackB->Draw("SAME");
}