void sim(Int_t nev=1) {
  AliSimulation simulator;
  simulator.MergeWith("../backgr/galice.root",3);
  simulator.SetWriteRawData("ALL","raw.root",kTRUE);

  simulator.SetDefaultStorage("local://$ALICE_ROOT");
  simulator.SetSpecificStorage("GRP/GRP/Data",
			       Form("local://%s",gSystem->pwd()));

  TStopwatch timer;
  timer.Start();
  simulator.Run(nev);
  timer.Stop();
  timer.Print();
}