a-a a-b a-i aaa aab aad aai aao aap aar aas ab- aba abb abd abi abo abp abr abs ad- ada adb add adi ado adp adr ads ai- aia aib aid aii aio aip air ais aoa aob aod aoi aoo aop aor aos ap- apa apb apd api apo app apr aps ar- ara arb ard ari aro arp arr ars as- asa asb asd asi aso asp asr ass b-p baa bab bad bai bao bap bar bas bba bbb bbd bbi bbo bbp bbr bbs bda bdb bdd bdi bdo bdp bdr bds bi- bia bib bid bii bio bip bir bis boa bob bod boi boo bop bor bos bpa bpb bpd bpi bpo bpp bpr bps bra brb brd bri bro brp brr brs bsa bsb bsd bsi bso bsp bsr bss daa dab dad dai dao dap dar das dba dbb dbd dbi dbo dbp dbr dbs dda ddb ddd ddi ddo ddp ddr dds di- dia dib did dii dio dip dir dis doa dob dod doi doo dop dor dos dpa dpb dpd dpi dpo dpp dpr dps dra drb drd dri dro drp drr drs dsa dsb dsd dsi dso dsp dsr dss i-d ia- iaa iab iad iai iao iap iar ias iba ibb ibd ibi ibo ibp ibr ibs ida idb idd idi ido idp idr ids iia iib iid iii iio iip iir iis io- ioa iob iod ioi ioo iop ior ios ipa ipb ipd ipi ipo ipp ipr ips ir- ira irb ird iri iro irp irr irs is- isa isb isd isi iso isp isr iss o-i oaa oab oad oai oao oap oar oas ob- oba obb obd obi obo obp obr obs oda odb odd odi odo odp odr ods oia oib oid oii oio oip oir ois oo- ooa oob ood ooi ooo oop oor oos op- opa opb opd opi opo opp opr ops or- ora orb ord ori oro orp orr ors os- osa osb osd osi oso osp osr oss p-p paa pab pad pai pao pap par pas pba pbb pbd pbi pbo pbp pbr pbs pda pdb pdd pdi pdo pdp pdr pds pia pib pid pii pio pip pir pis poa pob pod poi poo pop por pos ppa ppb ppd ppi ppo ppp ppr pps pra prb prd pri pro prp prr prs ps- psa psb psd psi pso psp psr pss ra- raa rab rad rai rao rap rar ras rba rbb rbd rbi rbo rbp rbr rbs rda rdb rdd rdi rdo rdp rdr rds ria rib rid rii rio rip rir ris roa rob rod roi roo rop ror ros rpa rpb rpd rpi rpo rpp rpr rps rra rrb rrd rri rrp rrr rrs rsa rsb rsd rsi rso rsp rsr rss saa sab sad sai sao sap sar sas sba sbb sbd sbi sbo sbp sbr sbs sda sdb sdd sdi sdo sdp sdr sds sia sib sid sii sio sip sir sis soa sob sod soi soo sop sor sos spa spb spd spi spo spp spr sps sr- sra srb srd sri sro srp srr srs ss- ssa ssb ssd ssi sso ssp ssr sss