void kpipi0(const char *filename="skimmed_proc11_prompt_leto_afterBCS_ta_myflag_md0pi.root", const char *outfilename= "kpipi0.root")  
{
  // Read your input file
  TFile *f = new TFile(filename,"READ");
  TTree *tree = (TTree*) f->Get("DstD0PiKK");
  
  Double_t Dz_M, Dst_M, Dst_isSignalAcceptMissingGamma, DzPi_M;
  Int_t my_flag;

  tree->SetBranchAddress("Dz_M",&Dz_M);
  tree->SetBranchAddress("Dst_M",&Dst_M);
  tree->SetBranchAddress("DzPi_M",&DzPi_M);
  tree->SetBranchAddress("Dst_isSignalAcceptMissingGamma",&Dst_isSignalAcceptMissingGamma);  
  tree->SetBranchAddress("my_flag",&my_flag);
    
  TFile *f1 = new TFile(outfilename,"RECREATE");
  TTree *t1 = new TTree("d0pi_distributions","tTREE");//creating a tree 
  TTree *t2 = new TTree("d0_distributions","tTREE");//creating a tree 	
  Double_t d0pi_kk, d0pi_kpipi0, d0pi_e, d0pi_kpi, d0pi_mu, d0_kk, d0_kpipi0, d0_e, d0_kpi, d0_mu;

  
  TBranch *b_d0pi_kpipi0=t1->Branch("d0pi_kpipi0",&d0pi_kpipi0,"d0pi_kpipi0/D");
  TBranch *b_d0_kpipi0=t2->Branch("d0_kpipi0",&d0_kpipi0,"d0_kpipi0/D");
  
  
  // Loop over candidates
  Long64_t nentries = tree->GetEntriesFast();
  for (Long64_t i=0; i<nentries; i++){
    tree->GetEntry(i);
        
    //kpipi0
    if(my_flag==4||my_flag==7||my_flag==8||my_flag==16||my_flag==20||my_flag==49||my_flag==207||my_flag==218||my_flag==225||my_flag==503){
       d0pi_kpipi0=DzPi_M;
       d0_kpipi0=Dz_M;
      if(Dz_M>1.855&&Dz_M<1.875)
	{
	  b_d0pi_kpipi0->Fill();
	  t1->Fill();
	}
      if(DzPi_M>2.009&&DzPi_M<2.011)
	{
	  d0_kpipi0=Dz_M;
	  b_d0_kpipi0->Fill();
	  t2->Fill();
	}
      
     
	}
  }   
  
  t1->Write();
  t2->Write();	
  f1->Close();
  
}