void FConvo() {
   double var_rand = 0, FWHM = 0, bin_sigma,cont;
   auto myRand = new TRandom();

   TFile *file1 = new TFile("result.root");
   TFile *file2 = new TFile("result1.root");
   TFile *file3 = new TFile("result2.root");
   
   Int_t binN=500;

   auto NearDet_edep1 = new TH1D("NearDet_edep1",";Energy (MeV);Counts keV",binN,0,600.0);
   auto NearDet_edep2 = new TH1D("NearDet_edep2",";Energy (MeV);Counts keV",binN,0,600.0);
   auto NearDet_edep3 = new TH1D("NearDet_edep3",";Energy (MeV);Counts keV",binN,0,600.0);

   TH1D *h1 = (TH1D*)file1->Get("Ntuple1;1");
   TH2D *h2 = (TH2D*)file2->Get("Ntuple1;1");
   TH2D *h3 = (TH2D*)file3->Get("Ntuple1;1");

   for (int k = 0; k<binN; k++) {
      FWHM = 46/1000.0; // in keV
      bin_sigma = FWHM /2.35;
      Double_t cent= h1->GetBinCenter(k);
      Int_t counts = h1->GetBinContent(k);
      for (int l=0; l<counts; l++) {
         Double_t var_rand=myRand->Gaus(cent,bin_sigma);
         NearDet_edep1->Fill(var_rand);
      }
   }

   for (int k = 0; k<binN; k++) {
      FWHM = 46/1000.0; // in keV
      bin_sigma = FWHM /2.35;
      Double_t cent= h2->GetBinCenter(k);
      Int_t counts = h2->GetBinContent(k);
      for (int l=0; l<counts; l++) {
         Double_t var_rand=myRand->Gaus(cent,bin_sigma);
         NearDet_edep2->Fill(var_rand);
      }
   }


  for (int k = 0; k<binN; k++) {
      FWHM = 46/1000.0; // in keV
      bin_sigma = FWHM /2.35;
      Double_t cent= h3->GetBinCenter(k);
      Int_t counts = h3->GetBinContent(k);
      for (int l=0; l<counts; l++) {
         Double_t var_rand=myRand->Gaus(cent,bin_sigma);
         NearDet_edep3->Fill(var_rand);
      }
   }

   auto c1 = new TCanvas("c1", "",1800,1400);
   NearDet_edep1->Draw(); NearDet_edep1->SetStats(0);
   NearDet_edep2->Draw("SAME"); NearDet_edep2->SetStats(0);
   NearDet_edep3->Draw("SAME"); NearDet_edep3->SetStats(0);

   auto leg = new TLegend(0.55,0.7,0.85,0.85);
   leg->AddEntry(h1,"Material1","L");
   leg->AddEntry(h2,"Material2","L");
   leg->AddEntry(h2,"Material3","L");
   leg->Draw();
}