void Count_cand_3D() {

#include <iostream.h>
#include <fstream.h>

  gROOT->Reset();

  // 
  //#######################################################
  // Change these values to meet your condition
  //#######################################################

  TString inFile_D0Kpi("histo_3D_D0Kpi_Run3.root");
  TString inFile_DchKpipi("histo_3D_DchKpipi_Run3.root");

  TString outFileName("Num_Cand.txt");

  enum { nbinsx = 5,
         nbinsy = 5,
         nbinsz = 5 };

  // ######################################################
  cout << "start";

  // Open input files and get histograms
  TFile * f1 = new TFile(inFile_D0Kpi);
  f1->ls();
  TH3D * BchD0Kpi_peak = (TH3D *)f1->Get("BpBm_BchD_peak;1");
  TH3D * BchD0Kpi_side = (TH3D *)f1->Get("BpBm_BchD_side;1");
  TH3D * BchD0Kpi_sub = (TH3D *)f1->Get("BpBm_BchD_sub;1");

  TFile * f2 = new TFile(inFile_DchKpipi);
  f2->ls();
  TH3D * B0DchKpipi_peak = (TH3D *)f2->Get("B0B0bar_B0D_peak;1");
  TH3D * B0DchKpipi_side = (TH3D *)f2->Get("B0B0bar_B0D_side;1");
  TH3D * B0DchKpipi_sub = (TH3D *)f2->Get("B0B0bar_B0D_sub;1");

  // Sum entries.
  int sum_BchD0Kpi_peak(0);
  int sum_BchD0Kpi_side(0);
  int sum_BchD0Kpi_sub(0);
  int sum_B0DchKpipi_peak(0);
  int sum_B0DchKpipi_side(0);
  int sum_B0DchKpipi_sub(0);
  for (int i=0; i<nbinsx; i++) {
    for (int j=0; j<nbinsy; j++) {
      for (int k=0; k<nbinsz; k++) {
	sum_BchD0Kpi_peak += BchD0Kpi_peak->GetBinContent(i+1,j+1,k+1);
	sum_BchD0Kpi_side += BchD0Kpi_side->GetBinContent(i+1,j+1,k+1);
	sum_BchD0Kpi_sub += BchD0Kpi_sub->GetBinContent(i+1,j+1,k+1);
	sum_B0DchKpipi_peak += B0DchKpipi_peak->GetBinContent(i+1,j+1,k+1);
	sum_B0DchKpipi_side += B0DchKpipi_side->GetBinContent(i+1,j+1,k+1);
	sum_B0DchKpipi_sub += B0DchKpipi_sub->GetBinContent(i+1,j+1,k+1);
      }
    }
  }
  cout << sum_BchD0Kpi_peak << endl;
  cout << sum_BchD0Kpi_side << endl;
  cout << sum_BchD0Kpi_sub << endl;
  cout << sum_B0DchKpipi_peak << endl;
  cout << sum_B0DchKpipi_side << endl;
  cout << sum_B0DchKpipi_sub << endl;

  // Open output file and save results. #####
  ofstream outFile(outFileName); //open output file
  if (!outFile) {
    cout << "Cannot open file " << outFile << endl;
  }
  outFile.setf(ios::fixed);
  outFile.setf(ios::showpoint);
  outFile << "BchD0Kpi_peak = " << sum_BchD0Kpi_peak  << endl;
  outFile << "BchD0Kpi_side = " << sum_BchD0Kpi_side  << endl;
  outFile << "BchD0Kpi_sub = " << sum_BchD0Kpi_sub  << endl;
  outFile << "B0DchKpipi_peak = " << sum_B0DchKpipi_peak  << endl;
  outFile << "B0DchKpipi_side = " << sum_B0DchKpipi_side  << endl;
  outFile << "B0DchKpipi_sub = " << sum_B0DchKpipi_sub  << endl;
  outFile.close();


}