-er a-a a-b a-i aaa aab aad aae aai aao aap aar aas ab- aba abb abd abe abi abo abp abr abs ad- ada adb add ade adi ado adp adr ads aea aeb aed aee aei aeo aep aer aes ai- aia aib aid aie aii aio aip air ais aoa aob aod aoe aoi aoo aop aor aos ap- apa apb apd ape api apo app apr aps ar- ara arb ard are ari aro arp arr ars as- asa asb asd ase asi aso asp asr ass b-p baa bab bad bae bai bao bap bar bas bba bbb bbd bbe bbi bbo bbp bbr bbs bda bdb bdd bde bdi bdo bdp bdr bds be- bea beb bed bee bei beo bep ber bes bi- bia bib bid bie bii bio bip bir bis boa bob bod boe boi boo bop bor bos bpa bpb bpd bpe bpi bpo bpp bpr bps bra brb brd bre bri bro brp brr brs bsa bsb bsd bse bsi bso bsp bsr bss daa dab dad dae dai dao dap dar das dba dbb dbd dbe dbi dbo dbp dbr dbs dda ddb ddd dde ddi ddo ddp ddr dds de- dea deb ded dee dei deo dep der des di- dia dib did die dii dio dip dir dis doa dob dod doe doi doo dop dor dos dpa dpb dpd dpe dpi dpo dpp dpr dps dra drb drd dre dri dro drp drr drs dsa dsb dsd dse dsi dso dsp dsr dss eaa eab ead eae eai eao eap ear eas eba ebb ebd ebe ebi ebo ebp ebr ebs ed- eda edb edd ede edi edo edp edr eds eea eeb eed eee eeo eep eer ees eia eib eid eie eii eio eip eir eis eo- eoa eob eod eoe eoi eoo eop eor eos ep- epa epb epd epe epi epo epp epr eps era erb erd ere eri ero erp err ers es- esa esb esd ese esi eso esp esr ess i-d ia- iaa iab iad iae iai iao iap iar ias iba ibb ibd ibe ibi ibo ibp ibr ibs ida idb idd ide idi ido idp idr ids ie- iea ied iee iei iep ier ies iia iib iid iie iii iio iip iir iis io- ioa iob iod ioe ioi ioo iop ior ios ipa ipb ipd ipe ipi ipo ipp ipr ips ir- ira irb ird ire iri iro irp irr irs is- isa isb isd ise isi iso isp isr iss o-i oaa oab oad oae oai oao oap oar oas ob- oba obb obd obe obi obo obp obr obs oda odb odd ode odi odo odp odr ods oea oeb oed oee oei oeo oep oer oes oia oib oid oie oii oio oip oir ois oo- ooa oob ood ooi ooo oop oor oos op- opa opb opd ope opi opo opp opr ops or- ora orb ord ore ori oro orp orr ors os- osa osb osd ose osi oso osp osr oss p-p paa pab pad pae pai pao pap par pas pba pbb pbd pbe pbi pbo pbp pbr pbs pda pdb pdd pde pdi pdo pdp pdr pds pea peb ped pee pei peo pep per pes pia pib pid pie pii pio pip pir pis poa pob pod poe poi poo pop por pos ppa ppb ppd ppe ppi ppo ppp ppr pps pra prb prd pre pri pro prp prr prs ps- psa psb psd pse psi pso psp psr pss ra- raa rab rad rae rai rao rap rar ras rba rbb rbd rbe rbi rbo rbp rbr rbs rda rdb rdd rde rdi rdo rdp rdr rds re- rea reb red ree rei reo rep rer res ria rib rid rie rii rio rip rir ris roa rob rod roe roi roo rop ror ros rpa rpb rpd rpe rpi rpo rpp rpr rps rra rrb rrd rri rrp rrr rrs rsa rsb rsd rse rsi rso rsp rsr rss saa sab sad sae sai sao sap sar sas sba sbb sbd sbe sbi sbo sbp sbr sbs sda sdb sdd sde sdi sdo sdp sdr sds se- sea seb sed see sei seo sep ser ses sia sib sid sie sii sio sip sir sis soa sob sod soe soi soo sop sor sos spa spb spd spe spi spo spp spr sps sr- sra srb srd sre sri sro srp srr srs ss- ssa ssb ssd sse ssi sso ssp ssr sss