-er bbb bbe bbg bbk bbn bbr be- beb bee beg bek ben ber bgb bge bgg bgk bgn bgr bkb bke bkg bkk bkn bkr bnb bne bng bnk bnn bnr brb bre brg brk brn brr ebb ebe ebg ebk ebn ebr eeb eee eeg eek een eer egb ege egg egn egr ekb eke ekg ekr en- enb ene eng enk enn enr erb ere erg erk ern err gbe gbg gbk gbn gbr ge- geb gee geg gek gen ger ggb ggg ggn ggr gkb gkn gnb gne gnn gnr grb gre grg grk grn grr kbb kbe kbk kbn kbr ke- keb kee keg kek ken ker kgb kkb kke kkk kkn kkr kn- kne kng knk knn knr krg krk krn krr nbb nbe nbg nbk nbn nbr ne- neb nee neg nek nen ner ngb nge ngg ngk ngn nke nkk nkn nkr nnb nne nng nnk nnn nrb nre nrg nrk nrn nrr rbb rbe rbg rbk rbn rbr re- reb ree reg rek ren rer rgb rge rgg rgk rgn rgr rkb rke rkg rkk rnb rng rnn rnr rrb rrg rrk rrn rrr