{
  TRandom3 *EG = new TRandom3(0);

    double npe = 1;
  double gain = 60;
  double sig = 6;
  double xtalk = 0.15;
  double ped = 100;
  double sig_ped = 7;
  
  int ntot = 1;
  TH1F* hh[16];
  char hname[256], htitle[256];

  for(int i = 0; i<ntot; i++)
    {
      sprintf(hname,"histo_ch%02d",i);
      sprintf(htitle,"ADC Channel #%02d; ADC; Counts",i);
      hh[i] = new TH1F(hname,htitle,2000,0,2000);
    }
  TH1F* hh_sum = new TH1F("histo_total","Sum of all channels; ADC; Counts", 5000,0,5000);
  
  for(int i = 0; i<10000; i++)
    {
      double adc_sum = 0;
      for(int j = 0; j<ntot; j++)
	{
	  int npixel = EG->Poisson(npe);
	  npixel += EG->Poisson((double)npixel*xtalk);
	  double width = sqrt(sig_ped*sig_ped + (double)npixel*sig*sig);
	  double adc_tmp = EG->Gaus(ped+gain*(double)npixel,width);
	  hh[j]->Fill(adc_tmp);
	  adc_sum += adc_tmp;
	}
      hh_sum->Fill(adc_sum);
      if((i+1)%1000 == 0) printf("%d events generated ...\n", i+1);
    }
  hh_sum->Draw();
}