def METHOD_NAME(pu):
    indir = '/eos/user/b/bfontana/Samples/' #indir = '/home/bfontana/'
    filename_suff = 'step3_ttbar_PU' + str(pu) #filename_suff = 'hadd_out_PU' + str(pu)
    fNames = [ 'file:' + x for x in glob.glob(os.path.join(indir, filename_suff + '*.root')) ]
    print(indir, filename_suff, pu, fNames)
    for _ in range(4):
        fNames.extend(fNames)
    if len(fNames)==0:
        print('Used globbing: ', glob.glob(os.path.join(indir, filename_suff + '*.root')))
        raise ValueError('No input files!')
    keep = 'keep *'
    drop1 = 'drop CSCDetIdCSCALCTPreTriggerDigiMuonDigiCollection_simCscTriggerPrimitiveDigis__HLT'
    drop2 = 'drop HGCRecHitsSorted_HGCalRecHit_HGC*E*RecHits_*'
    return cms.Source("PoolSource",
                      fileNames = cms.untracked.vstring(fNames),
                      inputCommands = cms.untracked.vstring(keep, drop1, drop2),
                      duplicateCheckMode = cms.untracked.string("noDuplicateCheck"))