-er b-p bbb bbe bbo bbp bbr be- beb bee beo bep ber bez bob boe boo bop bor boz bpb bpe bpo bpp bpr brb bre bro brp brr brz bze bzo bzp bzr bzz ebb ebe ebo ebp ebr eeb eee eeo eep eer eo- eob eoe eoo eop eor ep- epb epe epo epp epr epz erb ere ero erp err erz eze ezo ezr ezz ob- obb obe obo obp obr oeb oee oeo oep oer oo- oob ooo oop oor op- opb ope opo opp opr or- orb ore oro orp orr orz oze ozo ozz p-p pbb pbe pbo pbp pbr pbz peb pee peo pep per pez pob poe poo pop por poz ppb ppe ppo ppp ppr ppz prb pre pro prp prr prz pzp rbb rbe rbo rbp rbr re- reb ree reo rep rer rez rob roe roo rop ror roz rpb rpe rpo rpp rpr rpz rrb rrp rrr rzb rze rzo zbb zbr zeb zee zeo zep zer zez zo- zob zoe zoo zor zpe zpo zpp zpr zro zrp zzr zzz