{
   gROOT->Reset();
   TChain *ch = new TChain("TTT");
   ch->Add("file1.root");
   ch->Add("file2.root");
   Float_t Q2;
   
   TBranch *b_Q2 =TTT->GetBranch("Q2");
   
   b_Q2->SetAddress(&Q2);

   Long64_t localEntry = ch->LoadTree(5);
   b_Q2->GetEntry(localEntry);
   cout<<Q2<<endl;       
   return 0;
 }