diff --git a/parallel.cpp b/parallel.cpp
index e1ea79a..33be6de 100644
--- a/parallel.cpp
+++ b/parallel.cpp
@@ -12,6 +12,8 @@
 #include "TROOT.h"
 #include "ROOT/TThreadedObject.hxx"
 #include "ROOT/TTreeProcessorMT.hxx" 
+#include <memory>
+#include <vector>
 
 // mod = 0, 1, 2
 // row = 1, 2, 3
@@ -25,7 +27,7 @@ const double ExRange[2] = {-0.5, 3.5};
 const double ExRel = 0.05; //MeV
 const int nBin = (ExRange[1] - ExRange[0])/ExRel;
 
-#define SAVETREE false
+#define SAVETREE true
 
 //^====================================
 TH1F * haha[MAXMOD][MAXROW][MAXPStrip];
@@ -35,6 +37,8 @@ TH2F * dudu[MAXMOD][MAXROW];
 TH1F * hEx;
 
 //^====================================
+
+
 void parallel(){
 
 
@@ -73,6 +77,8 @@ void parallel(){
 
   hEx = new TH1F("hEx", "Ex", 10*nBin, ExRange[0], ExRange[1]);
 
+  ROOT::TThreadedObject<TH1F> phEx("hEx", "Ex", 10*nBin, ExRange[0], ExRange[1]);
+
   //^=========================== tree
   int nThreads = 4;
   ROOT::EnableImplicitMT(nThreads);
@@ -87,7 +93,9 @@ void parallel(){
   const double y2 = 2.005;
 
   TFile * newFile = nullptr;
-  TTree * newTree = nullptr;
+
+  ROOT::TThreadedObject<TTree> pTree;
+  std::shared_ptr<TTree> pTree_a[nThreads];
 
   Double_t Ex_org;
   Double_t Ex_C;
@@ -98,16 +106,32 @@ void parallel(){
   Double_t thetaCM;
 
   if( SAVETREE ){  
-    newFile = new TFile("Cali_132Sn_pal.root", "recreate");
+    newFile = new TFile("test.root", "recreate");
 
-    newTree = new TTree("tree", "Calibred Ex");
-    newTree->Branch("Ex_org", &Ex_org, "Ex_org/D");
-    newTree->Branch("mod",    &mod_C, "mod/I");
-    newTree->Branch("row",    &row_C, "row/I");
-    newTree->Branch("pstrip", &pStrip_C, "pstrip/I");
-    newTree->Branch("Ex", &Ex_C, "Ex/D");
-    newTree->Branch("z", &z, "z/D");
-    newTree->Branch("thetaCM", &thetaCM, "thetaCM/D");
+    // newTree = new TTree("tree", "Calibred Ex");
+    // newTree->Branch("Ex_org", &Ex_org, "Ex_org/D");
+    // newTree->Branch("mod",    &mod_C, "mod/I");
+    // newTree->Branch("row",    &row_C, "row/I");
+    // newTree->Branch("pstrip", &pStrip_C, "pstrip/I");
+    // newTree->Branch("Ex", &Ex_C, "Ex/D");
+    // newTree->Branch("z", &z, "z/D");
+    // newTree->Branch("thetaCM", &thetaCM, "thetaCM/D");
+
+    for( int i = 0; i < nThreads; i++ ){
+
+      pTree_a[i] = std::make_shared<TTree>("tree", "Calibrated Ex");
+    
+      pTree_a[i]->Branch("Ex_org", &Ex_org, "Ex_org/D");
+      pTree_a[i]->Branch("mod",    &mod_C, "mod/I");
+      pTree_a[i]->Branch("row",    &row_C, "row/I");
+      pTree_a[i]->Branch("pstrip", &pStrip_C, "pstrip/I");
+      pTree_a[i]->Branch("Ex", &Ex_C, "Ex/D");
+      pTree_a[i]->Branch("z", &z, "z/D");
+      pTree_a[i]->Branch("thetaCM", &thetaCM, "thetaCM/D");
+
+      pTree.SetAtSlot(i, pTree_a[i]);
+
+    }
   }
 
   std::mutex treeMuTex;
@@ -181,16 +205,22 @@ void parallel(){
 
       dudu[m][r]->Fill(p, Ex_C);
 
-      hEx->Fill( *Ex/1000);
+      hEx->Fill( *Ex/1000.);
 
-      if( SAVETREE ) {
-        newFile->cd();
-        treeMuTex.lock();
-        newTree->Fill();
-      }
+      // if( SAVETREE ) {
+      //   newFile->cd();
+      //   treeMuTex.lock();
+      //   newTree->Fill();
+      // }
 
       treeMuTex.unlock();
 
+      phEx->Fill(Ex_C);
+
+      if( SAVETREE ) {
+        pTree->Fill();
+      }
+
     }
 
   };
@@ -200,12 +230,28 @@ void parallel(){
 
   if( SAVETREE ) {
     newFile->cd();
-    newTree->Write();
-    printf("============== %llu\n", newTree->GetEntries());
+
+    TList list;
+    for (int i = 0; i < pTree.GetNSlots(); ++i) {
+      if( pTree.GetAtSlot(i)->GetEntries() == 0 ) continue;
+      list.Add(pTree.GetAtSlot(i).get());
+    }
+
+    TTree* mergedTree = TTree::MergeTrees(&list);
+    mergedTree->Write("", TObject::kWriteDelete);
+    printf("============== %llu\n", mergedTree->GetEntries());
+    
     newFile->Close();
   }
 
 
+  auto kEx = phEx.Merge();
+
+
+  // kEx->SetLineColor(2);
+  // kEx->DrawCopy();
+  // hEx->Draw("same");
+
   // gStyle->SetOptStat("");
 
   // TCanvas * canvas = new TCanvas("canvas", "canvas", 2100, 1500);
@@ -223,9 +269,9 @@ void parallel(){
   // canvas->cd(8); dudu[2][1]->Draw("colz");
   // canvas->cd(9); dudu[2][2]->Draw("colz");
 
-  TCanvas * canvasEx = new TCanvas("canvasEx", "canvasEx", 800, 400);
-  canvasEx->cd();
-  hEx->Draw();
+  // TCanvas * canvasEx = new TCanvas("canvasEx", "canvasEx", 800, 400);
+  // canvasEx->cd();
+  // hEx->Draw();
   
   // TCanvas * chaha = new TCanvas("chaha", "c haah", 500, 500);
   // haha[0][1][100]->Draw();