-er a-a a-b aaa aab aad aae aao aap aar aav ab- aba abb abd abe abo abp abr abv ad- ada adb add ade ado adp adr adv aea aeb aed aee aeo aep aer aev aoa aob aod aoe aoo aop aor aov ap- apa apb apd ape apo app apr apv ar- ara arb ard are aro arp arr arv av- ava avb avd ave avo avp avr b-p baa bab bad bae bao bap bar bav bba bbb bbd bbe bbo bbp bbr bda bdb bdd bde bdo bdp bdr bdv be- bea beb bed bee beo bep ber bev boa bob bod boe boo bop bor bov bpa bpb bpd bpe bpo bpp bpr bpv bra brb brd bre bro brp brr brv bva bvb bvd bve bvo bvp bvr bvv daa dab dad dae dao dap dar dav dba dbb dbd dbe dbo dbp dbr dbv dda ddb ddd dde ddo ddp ddr de- dea deb ded dee deo dep der dev doa dob dod doe doo dop dor dov dpa dpb dpd dpe dpo dpp dpr dpv dra drb drd dre dro drp drr drv dva dvb dvd dve dvp dvr eaa eab ead eae eao eap ear eav eba ebb ebd ebe ebo ebp ebr ebv ed- eda edb edd ede edo edp edr eea eeb eed eee eeo eep eer eev eo- eoa eob eod eoe eoo eop eor ep- epa epb epd epe epo epp epr era erb erd ere ero erp err erv eva evb evd eve evo evp evr evv oaa oab oad oae oao oap oar oav ob- oba obb obd obe obo obp obr obv oda odb odd ode odo odp odr odv oea oeb oed oee oeo oep oer oo- ooa oob ood ooo oop oor oov op- opa opb opd ope opo opp opr opv or- ora orb ord ore oro orp orr orv ov- ova ovb ovd ove ovo ovp ovv p-p paa pab pad pae pao pap par pav pba pbb pbd pbe pbo pbp pbr pda pdb pdd pde pdo pdp pdr pdv pea peb ped pee peo pep per pev poa pob pod poe poo pop por pov ppa ppb ppd ppe ppo ppp ppr ppv pra prb prd pre pro prp prr prv pva pvb pvd pve pvo pvp pvr pvv ra- raa rab rad rae rao rap rar rav rba rbb rbd rbe rbo rbp rbr rda rdb rdd rde rdo rdp rdr rdv re- rea reb red ree reo rep rer rev roa rob rod roe roo rop ror rov rpa rpb rpd rpe rpo rpp rpr rpv rra rrb rrd rrp rrr rva rvb rvd rve rvo rvp rvr rvv v-a v-e vaa vab vad vae vao vap var vav vba vbd vbo vbr vbv vdb vdd vde vdo vdp vdr vdv vea veb ved vee veo vep ver voa vob vod voe voo vop vor vov vpa vpb vpd vpe vpo vpp vpr vra vrb vrd vre vrp vrr vva vvb vvo vvr vvv