-er b-p bbb bbd bbe bbo bbp bbr bbx bdb bdd bde bdo bdp bdr bdx be- beb bed bee beo bep ber bex bob bod boe boo bop bor box bpb bpd bpe bpo bpp bpr bpx brb brd bre bro brp brr brx bxb bxd bxo bxx dbb dbd dbe dbo dbp dbr dbx ddb ddd dde ddo ddp ddr ddx de- deb ded dee deo dep der dex dob dod doe doo dop dor dox dpb dpd dpe dpo dpp dpr drb drd dre dro drp drr drx dxd dxo dxp dxr dxx ebb ebd ebe ebo ebp ebr ebx ed- edb edd ede edo edp edr edx eeb eed eee eeo eep eer eex eo- eob eod eoe eoo eop eor ep- epb epd epe epo epp epr epx erb erd ere ero erp err ex- exd exe exo exp exr exx ob- obb obd obe obo obp obr obx odb odd ode odo odp odr oeb oed oee oeo oep oer oex oo- oob ood ooo oop oor oox op- opb opd ope opo opp opr opx or- orb ord ore oro orp orr orx ox- oxb oxo oxx p-p pbb pbd pbe pbo pbp pbr pbx pdb pdd pde pdo pdp pdr pdx peb ped pee peo pep per pex pob pod poe poo pop por pox ppb ppd ppe ppo ppp ppr ppx prb prd pre pro prp prr prx pxe pxr rbb rbd rbe rbo rbp rbr rbx rdb rdd rde rdo rdp rdr rdx re- reb red ree reo rep rer rex rob rod roe roo rop ror rox rpb rpd rpe rpo rpp rpr rpx rrb rrd rrp rrr rxp rxr xbe xbr xbx xdb xde xdr xed xee xep xer xex xod xoo xop xor xox xpb xpd xpe xpo xpp xrd xrx xxo xxp xxx