void BkgContrPlot(){
  const nPoints = 5;
  double Pbeam[5]={1.5,4.06,8.9,11.91,15};
 //  const nPoints = 2;
// double Pbeam[nPoints]={4.06,15};
//   // //No Cut, No Dipole --------------------------------------------------------------
//  double SigEl[nPoints]={1366.04, 1436.61};
//  double SigEl_err[nPoints]={2.66, 3.09};
//  double BkgEl[nPoints]={92.08, 89.21};
//  double BkgEl_err[nPoints]={0.47, 0.15};
//  double BkgElSec[nPoints]={9.50, 109.47};
//  double BkgElSec_err[nPoints]={0.34, 0.48};
//  double BkgInel[nPoints]={84.28, 392.15};
//  double BkgInel_err[nPoints]={0.39, 1.63};
//  double BkgInelSec[nPoints]={18.89, 105.88};
//  double BkgInelSec_err[nPoints]={0.57, 0.89};
//   // //[END]No Cut -------------------------------------------------------

 // //No Cut --------------------------------------------------------------
 //  double SigEl[5]={10963.6, 1364.94, 920.34, 1123.7, 1437.47};
 //  double SigEl_err[5]={11.87,3.34,1.32,0.81,2.15};
 //  double BkgEl[5]={391.96,92.01,89.99,90.78,96.32};
 //  double BkgEl_err[5]={1.28, 0.31, 0.33, 0.61, 0.14};
 //  double BkgElSec[5]={ 8.96,6.73,23.59,40.54 ,60.51};
 //  double BkgElSec_err[5]={0.23,0.13,0.37,0.29, 0.11};
 //  double BkgInel[5]={8.61,19.94,40.95, 58.44, 80.21};
 //  double BkgInel_err[5]={0.15, 0.13,  0.49, 0.66, 0.41};
 //  double BkgInelSec[5]={2.65, 5.10, 17.65, 32.51, 55.12};
 //  double BkgInelSec_err[5]={0.12, 0.19, 0.15, 0.39, 0.44};
 //  //[END]No Cut -------------------------------------------------------

  // //X&Y Cut --------------------------------------------------------------
  // double SigEl[5]={10762.9, 1362.56, 889.38, 1120.98, 1437.25};
  // double SigEl_err[5]={4.72, 2.65, 2.75, 2.13, 1.67};
  // double BkgEl[5]={177.16, 27.98, 22.26, 24.94, 28.42};
  // double BkgEl_err[5]={0.44, 0.23, 0.59, 0.26, 0.37};
  // double BkgElSec[5]={0.004, 0.035, 0.052, 0.11, 0.17};
  // double BkgElSec_err[5]={0.006, 0.004, 0.005, 0.01, 0.04};
  // double BkgInel[5]={1.09, 1.79, 2.09, 3.38, 5.17};
  // double BkgInel_err[5]={0.05, 0.09, 0.12, 0.08, 0.18};
  // double BkgInelSec[5]={0.042, 0.017, 0.071, 0.078, 0.12};
  // double BkgInelSec_err[5]={0.012, 0.009, 0.016, 0.011, 0.01};
  // //[END] X&Y Cut -------------------------------------------------------

 //M Cut --------------------------------------------------------------
  double SigEl_noCut[5]={10963.6, 1364.94, 920.34, 1123.7, 1437.47};
  double SigEl_err_noCut[5]={11.87,3.34,4.32,0.81,2.15};
  double SigEl_XY[5]={10762.9, 1362.56, 889.38, 1120.98, 1437.25};
  double SigEl_XY_err[5]={4.72, 2.65, 3.75, 2.13, 1.67};
  double SigEl[5]={10708.2,1357.74, 888.04,  1118.6,  1434.35, };
  double SigEl_err[5]={5.20,1.82, 2.66, 2.23, 1.70};
  double BkgEl[5]={63.99, 15.20, 10.66, 11.70, 13.27, };
  double BkgEl_err[5]={0.14,0.39, 0.24, 0.17, 0.27};
  double BkgElSec[5]={0.004, 0.007, 0.008, 0.028, 0.054};
  double BkgElSec_err[5]={0.006, 0.006, 0.011, 0.007, 0.019};
  double BkgInel[5]={1.05, 0.88, 0.91, 1.55, 2.59};
  double BkgInel_err[5]={0.06, 0.08, 0.05, 0.12, 0.17};
  double BkgInelSec[5]={0.033, 0.002, 0.019, 0.014, 0.034};
  double BkgInelSec_err[5]={0.016, 0.004, 0.005, 0.005, 0.005};
  //[END] M Cut -------------------------------------------------------
 

  double BkgTOT[nPoints]; double BkgTOT_err[nPoints];
  // double Eff[5]; double Eff_err[5];
  // double Eff_noCut[5]; double Eff_err_noCut[5];
  // // double SigEl[5]={9563.84,1355.74,898.96,1119.26,1435.0};
  // // double SigEl_err[5]={6.87,4.67,6.43,0.22,0.89};
  // // double BkgEl[5]={ 2.80,15.64,10.66,11.80,13.47};
  // // double BkgEl_err[5]={0.10,0.19,0.25,0.0059,0.13};
  // // double BkgElSec[5]={0.0042,0.007,0.017, 0.021,0.035};
  // // double BkgElSec_err[5]={0.0059,0.005,0.003,0.001,0.004};

  for(int ip=0;ip<nPoints;ip++){
    //z=x/y => (dz/z)^2 = (dx/x)^2+(dy/y)^2 => dz*y=sqrt(dx^2+(z*dy)^2)

    // Eff[ip] = 100.*SigEl[ip]/SigEl_noCut[ip];
    // Eff_err[ip] = 100.*SigEl_err[ip]/SigEl_noCut[ip];
    // Eff_noCut[ip] = 100.*SigEl_XY[ip]/SigEl_noCut[ip];
    // Eff_err_noCut[ip] = 100.*SigEl_XY_err[ip]/SigEl_noCut[ip];
    // //    Eff_err[ip] = 100.*sqrt(SigEl_err[ip]*SigEl_err[ip]+Eff[ip]*Eff[ip]*SigEl_XY_err[ip]*SigEl_XY_err[ip])/SigEl_XY[ip];

    BkgEl[ip] = 100.*BkgEl[ip]/SigEl[ip];
    BkgEl_err[ip] = 100.*sqrt(BkgEl_err[ip]*BkgEl_err[ip]+BkgEl[ip]*BkgEl[ip]*SigEl_err[ip]*SigEl_err[ip])/SigEl[ip];


    BkgElSec[ip] = 100.*BkgElSec[ip]/SigEl[ip];
    BkgElSec_err[ip] = 100.*sqrt(BkgElSec_err[ip]*BkgElSec_err[ip]+BkgElSec[ip]*BkgElSec[ip]*SigEl_err[ip]*SigEl_err[ip])/SigEl[ip];

    BkgInel[ip] = 100.*BkgInel[ip]/SigEl[ip];
    BkgInel_err[ip] =100.*sqrt(BkgInel_err[ip]*BkgInel_err[ip]+BkgInel[ip]*BkgInel[ip]*SigEl_err[ip]*SigEl_err[ip])/SigEl[ip];

    BkgInelSec[ip] =  100.*BkgInelSec[ip]/SigEl[ip];
    BkgInelSec_err[ip] = 100.*sqrt(BkgInelSec_err[ip]*BkgInelSec_err[ip]+BkgInelSec[ip]*BkgInelSec[ip]*SigEl_err[ip]*SigEl_err[ip])/SigEl[ip];

    BkgTOT[ip] = BkgEl[ip]+BkgElSec[ip]+BkgInel[ip]+BkgInelSec[ip];
    BkgTOT_err[ip] = sqrt(BkgEl_err[ip]*BkgEl_err[ip]+BkgElSec_err[ip]*BkgElSec_err[ip]+BkgInel_err[ip]*BkgInel_err[ip]+BkgInelSec_err[ip]*BkgInelSec_err[ip]);
    cout<<"TOT @"<<Pbeam[ip]<<" = "<<BkgTOT[ip] <<" +/- "<<BkgTOT_err[ip]<<endl;
  }

 //  TGraphErrors *gr_Sig = new TGraphErrors(nPoints,Pbeam,Eff,0,Eff_err);
 //  gr_Sig->SetMarkerColor(kOrange+7);
 //  gr_Sig->SetMarkerSize(2.);
 //  gr_Sig->SetMarkerStyle(20);
 //  // gr_Sig->Draw("AP");

 // TGraphErrors *gr_Sig_noCut = new TGraphErrors(nPoints,Pbeam,Eff_noCut,0,Eff_err_noCut);
 //  gr_Sig_noCut->SetMarkerColor(kOrange+1);
 //  gr_Sig_noCut->SetMarkerSize(2.);
 //  gr_Sig_noCut->SetMarkerStyle(20);
 // TMultiGraph *mgr = new TMultiGraph();
 // mgr->Add(gr_Sig);
 // mgr->Add(gr_Sig_noCut);
 // mgr->Draw("AP");

 // TLegend *leg = new TLegend(0.45,0.2,0.95,0.55);
 //  leg->SetHeader("Signal efficiency");
 // leg->SetTextAlign(12);
 // leg->SetTextSize(0.04);
 // leg->SetFillColor(0);
 // // leg->AddEntry(gr_Sig,"Signal","ep");
 // leg->AddEntry(gr_Sig_noCut,"after X&Y cut","ep");
 // leg->AddEntry(gr_Sig,"after M cut","ep");
 // leg->Draw();

 //  // gr_Sig_noCut->Draw("AP");

  TGraphErrors *gr_BkgTot = new TGraphErrors(nPoints,Pbeam,BkgTOT,0,BkgTOT_err);
  gr_BkgTot->SetMarkerColor(1);
  gr_BkgTot->SetMarkerSize(2.);
  gr_BkgTot->SetMarkerStyle(20);

  TGraphErrors *gr_BkgEl = new TGraphErrors(nPoints,Pbeam,BkgEl,0,BkgEl_err);
  gr_BkgEl->SetMarkerColor(kRed+1);
  gr_BkgEl->SetMarkerSize(2.);
  gr_BkgEl->SetMarkerStyle(21);
 TGraphErrors *gr_BkgElSec = new TGraphErrors(nPoints,Pbeam,BkgElSec,0,BkgElSec_err);
  gr_BkgElSec->SetMarkerColor(kRed-7);
  gr_BkgElSec->SetMarkerSize(2.);
  gr_BkgElSec->SetMarkerStyle(21);
 TGraphErrors *gr_BkgInel = new TGraphErrors(nPoints,Pbeam,BkgInel,0,BkgInel_err);
  gr_BkgInel->SetMarkerColor(kGreen+4);
  gr_BkgInel->SetMarkerSize(2.);
  gr_BkgInel->SetMarkerStyle(21);
 TGraphErrors *gr_BkgInelSec = new TGraphErrors(nPoints,Pbeam,BkgInelSec,0,BkgInelSec_err);
  gr_BkgInelSec->SetMarkerColor(kGreen-2);
  gr_BkgInelSec->SetMarkerSize(2.);
  gr_BkgInelSec->SetMarkerStyle(21);
  TMultiGraph *mgr = new TMultiGraph();
  //mgr->Add(gr_Sig);
  
  mgr->Add(gr_BkgEl);
  mgr->Add(gr_BkgElSec);
  mgr->Add(gr_BkgInel);
  mgr->Add(gr_BkgInelSec);
mgr->Add(gr_BkgTot);
  mgr->Draw("AP");
  mgr->GetXaxis()->SetTitle("P_{beam}, GeV/c");
  mgr->GetYaxis()->SetTitle("N_{bkg}/N_{sig}, %");
  TLegend *leg = new TLegend(0.45,0.2,0.95,0.55);
  leg->SetHeader("Bkg with M cut");
 leg->SetTextAlign(12);
 leg->SetTextSize(0.04);
 leg->SetFillColor(0);
 // leg->AddEntry(gr_Sig,"Signal","ep");
 leg->AddEntry(gr_BkgEl,"elastic","ep");
 leg->AddEntry(gr_BkgElSec,"secondaries from elastic","ep");
 leg->AddEntry(gr_BkgInel,"inelastic","ep");
 leg->AddEntry(gr_BkgInelSec,"secondaries from inelastic","ep");
leg->AddEntry(gr_BkgTot,"Total","ep");
 leg->Draw();
//  //   leg->SetHeader("The Legend Title");
}