removeLastPoints( Int_t lastPoints=0 )
{

  gROOT->SetStyle("Plain"); 
  gStyle->SetOptTitle(0);
  const Int_t n = 5;
  
  Float_t y[n]  = {5.,7.,10.,14.,16.};
  Float_t ey[n] = {0.,0.,0.,0.,0.};
  
  Float_t x[n]  = {5.,7.,9.,13.,15.};
  Float_t ex[n] = {0.01,0.02,0.02,0.01,0.01};
  
  TGraphErrors *graph = new TGraphErrors(n,x,y,ex,ey); 
  //graph->Draw("A*");
  graph->Print();
  
  for (int i=graph->GetN()-lastPoints; i<graph->GetN(); i++)
    {
      cout << " <I> Removing point " << i <<  " of the graph " << endl;
      graph->RemovePoint(i);
    }
  cout << endl; 
  
  graph->Print();
  cout << endl; 
}