a-a a-b a-c aaa aab aac aak aam aao aap aar aas ab- aba abb abc abk abm abo abp abr abs ac- aca acb acc ack acm aco acp acr acs aka akb akc akk akm ako akp akr aks ama amb amc amk amm amo amp amr ams aoa aob aoc aok aom aoo aop aor aos ap- apa apb apc apk apm apo app apr aps ar- ara arb arc ark arm aro arp arr ars as- asa asb asc ask asm aso asp asr ass b-p baa bab bac bak bam bao bap bar bas bba bbb bbc bbk bbm bbo bbp bbr bbs bca bcb bcc bck bcm bco bcp bcr bcs bka bkb bkc bkk bkm bko bkp bkr bks bma bmb bmc bmk bmm bmo bmp bmr bms boa bob boc bok bom boo bop bor bos bpa bpb bpc bpm bpo bpp bpr bps bra brb brk brm bro brp brr brs bsa bsb bsc bsk bsm bso bsp bsr bss c-- caa cab cac cak cam cao cap car cas cba cbb cbc cbk cbm cbo cbp cbr cbs cca ccb ccc cck ccm cco ccp ccr ccs cka ckb ckc ckm cko cks cma cmb cmc cmk cmm cmo cmp cmr cms co- coa cob coc cok com coo cop cor cos cpa cpb cpc cpk cpm cpo cpp cpr cps cra crb crc crk crm cro crp crr crs csa csb csc csk csm cso csp csr css ka- kaa kab kac kak kam kao kap kar kas kba kbb kbc kbk kbm kbo kbp kbr kbs kca kcb kcc kck kcm kcp kcr kcs kkb kkc kkk kkm kkp kkr kks kma kmb kmc kmk kmm kmo kmp kms koa kob koc kok kom koo kop kor kos kpa kpc kpk kpm kpo kpp kpr kps kra krc krk kro krp krr krs ksa ksb ksc ksk ksm kso ksp ksr kss m-o m-r maa mab mac mak mam mao map mar mas mba mbb mbc mbk mbm mbo mbp mbr mbs mc- mca mcb mcc mck mcm mco mcp mcr mcs mka mkb mkc mkk mkm mko mkp mkr mks mma mmb mmc mmk mmm mmo mmp mmr mms moa mob moc mok mom moo mop mor mos mpa mpb mpc mpk mpm mpo mpp mpr mps mra mrb mrc mrk mrm mro mrp mrr mrs msa msb msc msk msm mso msp msr mss oaa oab oac oak oam oao oap oar oas ob- oba obb obc obk obm obo obp obr obs oc- oca ocb occ ock ocm oco ocp ocr ocs oka okb okc okk oko okp okr oks om- oma omb omc omm omo omp omr oms oo- ooa oob ooc ook oom ooo oop oor oos op- opa opb opc opk opm opo opp opr ops or- ora orb orc ork orm oro orp orr ors os- osa osb osc osk osm oso osp osr oss p-p paa pab pac pak pam pao pap par pas pba pbb pbc pbk pbm pbo pbp pbr pbs pca pcb pcc pck pcm pco pcp pcr pcs pka pkb pkc pkm pko pkp pkr pks pma pmb pmc pmk pmm pmo pmp pmr pms poa pob poc pok pom poo pop por pos ppa ppb ppc ppk ppm ppo ppp ppr pps pra prb prc prk prm pro prp prr prs ps- psa psb psc psk psm pso psp psr pss ra- raa rab rac rak ram rao rap rar ras rba rbb rbc rbk rbm rbo rbp rbr rbs rca rcb rcc rcm rco rcp rcr rcs rkb rkc rkk rkm rko rkp rks rma rmb rmc rmm rmo rmp rmr rms roa rob roc rok rom roo rop ror ros rpa rpb rpc rpk rpm rpo rpp rpr rps rra rrb rrc rrk rrm rrp rrr rrs rsa rsb rsc rsk rsm rso rsp rsr rss saa sab sac sak sam sao sap sar sas sba sbb sbc sbk sbm sbo sbp sbr sbs sca scb scc sck scm sco scp scr scs sk- ska skb skc skk skm sko skp skr sks sma smb smc smk smm smo smp smr sms soa sob soc sok som soo sop sor sos spa spb spc spk spm spo spp spr sps sr- sra srb src srk srm sro srp srr srs ss- ssa ssb ssc ssk ssm sso ssp ssr sss