-er bbb bbe bbg bbk bbn bbo bbr be- beb bee beg bek ben beo ber bgb bge bgg bgk bgn bgo bgr bkb bke bkg bkk bkn bko bkr bnb bne bng bnk bnn bno bnr bob boe bog bok bon boo bor brb bre brg brk brn bro brr ebb ebe ebg ebk ebn ebo ebr eeb eee eeg eek een eeo eer egb ege egg egn ego egr ekb eke ekg eko ekr en- enb ene eng enk enn eno enr eo- eob eoe eog eok eon eoo eor erb ere erg erk ern ero err gbe gbg gbk gbn gbo gbr ge- geb gee geg gek gen geo ger ggb ggg ggn ggo ggr gkb gkn gko gnb gne gnn gno gnr gob goe gog gok gon goo gor grb gre grg grk grn gro grr kbb kbe kbk kbn kbo kbr ke- keb kee keg kek ken keo ker kgb kgo kkb kke kkk kkn kkr kn- kne kng knk knn kno knr kob koe kog kok kon koo kor krg krk krn kro krr nbb nbe nbg nbk nbn nbo nbr ne- neb nee neg nek nen neo ner ngb nge ngg ngk ngn ngo nke nkk nkn nko nkr nnb nne nng nnk nnn nno no- nob noe nog nok non noo nor nrb nre nrg nrk nrn nro nrr ob- obb obe obg obk obn obo obr oeb oee oeg oen oeo oer oge ogg ogn ogo okb oke okg okk oko okr on- onb one ong onk onn ono onr oo- oob oog ook oon ooo oor or- orb ore org ork orn oro orr rbb rbe rbg rbk rbn rbo rbr re- reb ree reg rek ren reo rer rgb rge rgg rgk rgn rgo rgr rkb rke rkg rkk rko rnb rng rnn rno rnr rob roe rog rok ron roo ror rrb rrg rrk rrn rrr