{
   gROOT->ProcessLine(".L myvar.cpp");
   gROOT->ProcessLine(".L skim_athena.C");
   TChain *c1=new TChain("mytree");

   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.01.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.02.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.03.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.04.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.05.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.06.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.07.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.08.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.09.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.10.root");
   c1->Add("/rooms/bulls/alstone/skimming/pass2/em1trk/single_tight_em1trk_nohmx7-etacut.11.root");

   skim_athena  p1(c1);
   p1.analyze("test_em1trk.root");
}