text: import FWCore.ParameterSet.Config as cms
  import os
  
  source = cms.Source("EmptySource")
  
  generator = cms.EDFilter("SherpaGeneratorFilter",
    maxEventsToPrint = cms.int32(0),
    filterEfficiency = cms.untracked.double(1.0),
    crossSection = cms.untracked.double(-1),
    SherpaProcess = cms.string('ttbar_2j_MENLOPS_13TeV'),
    SherpackLocation = cms.string('/cvmfs/cms.cern.ch/phys_generator/gridpacks/slc7_amd64_gcc820/13TeV/sherpa/2.2.8'),
    SherpackChecksum = cms.string('4efdf38e0d189d58c65a554ef901d027'),
    FetchSherpack = cms.bool(True),
    SherpaPath = cms.string('./'),
    SherpaPathPiece = cms.string('./'),
    SherpaResultDir = cms.string('Result'),
    SherpaDefaultWeight = cms.double(1.0),
    SherpaParameters = cms.PSet(parameterSets = cms.vstring(
                               "MPI_Cross_Sections",
                               "Run"),
                                MPI_Cross_Sections = cms.vstring(
  				" MPIs in Sherpa, Model = Amisic:",
  				" semihard xsec = 39.5554 mb,",
  				" non-diffractive xsec = 17.0318 mb with nd factor = 0.3142."
                                                    ),
                                Run = cms.vstring(
  				" (run){",
  				" CORE_SCALE TTBar;",
  				" METS_BBAR_MODE 5;",
  				" NJET:=2; LJET:=2; QCUT:=20.;",
  				" ME_SIGNAL_GENERATOR Comix Amegic LOOPGEN;",
  				" OL_PREFIX={0} ".format(os.environ['CMS_OPENLOOPS_PREFIX']),
  				" LOOPGEN:=OpenLoops;",
  				" MI_HANDLER=Amisic;",
  				" NLO_SMEAR_THRESHOLD 1;",
  				" NLO_SMEAR_POWER 2;",
  				" HARD_DECAYS On;",
  				" HARD_SPIN_CORRELATIONS=1;",
  				" SOFT_SPIN_CORRELATIONS=1;",
  				" PDF_LIBRARY LHAPDFSherpa;",
  				" PDF_SET NNPDF31_nnlo_hessian_pdfas;",
  				" USE_PDF_ALPHAS=1;",
  				" BEAM_1=2212; BEAM_ENERGY_1=6500;",
  				" BEAM_2=2212; BEAM_ENERGY_2=6500;",
  				" STABLE[6] 0; WIDTH[6] 0; STABLE[24] 0;",
  				" EXCLUSIVE_CLUSTER_MODE 1;",
  				" HEPMC_TREE_LIKE=1;",
  				" PRETTY_PRINT=Off;",
  				"}(run)",
  				" (processes){",
  				" Process : 93 93 -> 6 -6 93{NJET};",
  				" Order (*,0); CKKW sqr(QCUT/E_CMS);",
  				" NLO_QCD_Mode MC@NLO {LJET};",
  				" ME_Generator Amegic {LJET};",
  				" RS_ME_Generator Comix {LJET};",
  				" Loop_Generator LOOPGEN {LJET};",
  				" Integration_Error 0.05 {3,4};",
  				" End process;",
  				"}(processes)"
                                                    ),
                               )
  )
  
  ProductionFilterSequence = cms.Sequence(generator)
  