a-a a-b aaa aab aag aao aap aar aas ab- aba abb abg abo abp abr abs ag- aga agb agg ago agp agr ags aoa aob aog aoo aop aor aos ap- apa apb apg apo app apr aps ar- ara arb arg aro arp arr ars as- asa asb asg aso asp asr ass b-p baa bab bag bao bap bar bas bba bbb bbg bbo bbp bbr bbs bga bgb bgg bgo bgp bgr bgs boa bob bog boo bop bor bos bpa bpb bpg bpo bpp bpr bps bra brb brg bro brp brr brs bsa bsb bsg bso bsp bsr bss g-p gaa gab gag gao gap gar gas gba gbg gbo gbp gbr gbs gga ggb ggg ggo ggp ggr ggs goa gob gog goo gop gor gos gpa gpb gpg gpo gpp gpr gps gra grb grg gro grp grr grs gsa gsb gsg gso gsp gsr gss oaa oab oag oao oap oar oas ob- oba obb obg obo obp obr obs oga ogg ogo ogp ogs oo- ooa oob oog ooo oop oor oos op- opa opb opg opo opp opr ops or- ora orb org oro orp orr ors os- osa osb osg oso osp osr oss p-p paa pab pag pao pap par pas pba pbb pbg pbo pbp pbr pbs pga pgb pgg pgo pgp pgr pgs poa pob pog poo pop por pos ppa ppb ppg ppo ppp ppr pps pra prb prg pro prp prr prs ps- psa psb psg pso psp psr pss ra- raa rab rag rao rap rar ras rba rbb rbg rbo rbp rbr rbs rga rgb rgg rgo rgp rgr rgs roa rob rog roo rop ror ros rpa rpb rpg rpo rpp rpr rps rra rrb rrg rrp rrr rrs rsa rsb rsg rso rsp rsr rss saa sab sag sao sap sar sas sba sbb sbg sbo sbp sbr sbs sga sgb sgg sgo sgp sgr sgs soa sob sog soo sop sor sos spa spb spg spo spp spr sps sr- sra srb srg sro srp srr srs ss- ssa ssb ssg sso ssp ssr sss