-er eee eef eek eel een eer ef- efe eff efl efr eke ekf ekl ekr ele elf elk ell eln elr en- ene enf enk enl enn enr ere erf erk erl ern err fee fef fek fel fen fer ffe fff ffk ffl ffn ffr fkf fkk fkl fle flf fll fln flr fne fnf fnk fnl fnn fnr fre frf frk frl frn frr ke- kee kef kek kel ken ker kff kke kkk kkl kkn kkr kl- klf klr kn- kne knf knk knl knn knr krf krk krl krn krr lee lef lek lel len ler lfe lff lfk lfl lfn lfr lkl lkr lle llf llk lll lln llr lne lnk lnl lnn lnr lrf lrk lrn lrr ne- nee nef nek nel nen ner nfe nff nfk nfl nfn nfr nke nkf nkk nkn nkr nle nlf nlk nll nln nlr nne nnf nnk nnl nnn nre nrf nrk nrl nrn nrr re- ree ref rek rel ren rer rfe rff rfk rfl rfn rfr rke rkf rkk rle rlf rll rln rlr rnn rnr rrf rrk rrl rrn rrr