{
   auto c1 = new TCanvas("c1","c1",600,400);
   auto hcontz = new TH2F("hcontz","Option CONTZ example ",40,-4,4,40,-20,20);
   float px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcontz->Fill(px-1,5*py);
      hcontz->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hcontz->Draw("CONTZ");
}