-er bbb bbe bbk bbm bbo bbr be- beb bee bek bem beo ber bez bkb bke bkk bkm bko bkr bmb bme bmk bmm bmo bmr bmz bob boe bok bom boo bor boz brb bre brk brm bro brr brz bze bzo bzr bzz ebb ebe ebk ebm ebo ebr eeb eee eek eem eeo eer ekb eke eko ekr em- emb eme emk emm emo emr eo- eob eoe eok eom eoo eor erb ere erk erm ero err erz eze ezo ezr ezz k-z kbb kbe kbk kbm kbo kbr kbz ke- keb kee kek kem keo ker kez kkb kke kkk kkm kkr kmb kme kmk kmm kmo kmz kob koe kok kom koo kor koz krk kro krr kzo m-o m-r mbb mbe mbk mbm mbo mbr meb mee mek mem meo mer mez mkb mke mkk mkm mko mkr mkz mmb mme mmk mmm mmo mmr mmz mob moe mok mom moo mor moz mrb mre mrk mrm mro mrr mrz mzb mzm ob- obb obe obk obm obo obr oeb oee oem oeo oer okb oke okk oko okr om- omb ome omm omo omr omz oo- oob ook oom ooo oor or- orb ore ork orm oro orr orz oze ozm ozo ozz rbb rbe rbk rbm rbo rbr re- reb ree rek rem reo rer rez rkb rke rkk rkm rko rkz rmb rme rmm rmo rmr rob roe rok rom roo ror roz rrb rrk rrm rrr rzb rze rzm rzo zbb zbm zbr zeb zee zek zem zeo zer zez zmb zmk zmm zo- zob zoe zok zom zoo zor zro zzr zzz