a-a a-b a-c a-t aaa aab aac aak aao aap aar aas aat ab- aba abb abc abk abo abp abr abs abt ac- aca acb acc ack aco acp acr acs act aka akb akc akk ako akp akr aks aoa aob aoc aok aoo aop aor aos aot ap- apa apb apc apk apo app apr aps apt ar- ara arb arc ark aro arp arr ars art as- asa asb asc ask aso asp asr ass ast at- ata atb atc ato atp atr ats att b-p baa bab bac bak bao bap bar bas bat bba bbb bbc bbk bbo bbp bbr bbs bbt bca bcb bcc bck bco bcp bcr bcs bct bka bkb bkc bkk bko bkp bkr bks bkt boa bob boc bok boo bop bor bos bot bpa bpb bpc bpo bpp bpr bps bpt bra brb brk bro brp brr brs brt bsa bsb bsc bsk bso bsp bsr bss bst bta btb btc btk bto btp btr bts btt c-- caa cab cac cak cao cap car cas cat cba cbb cbc cbk cbo cbp cbr cbs cbt cca ccb ccc cck cco ccp ccr ccs cct cka ckb ckc cko cks ckt co- coa cob coc cok coo cop cor cos cot cpa cpb cpc cpk cpo cpp cpr cps cpt cra crb crc crk cro crp crr crs crt csa csb csc csk cso csp csr css cst cta ctb ctc ctk cto ctp ctr cts ctt k-t ka- kaa kab kac kak kao kap kar kas kat kba kbb kbc kbk kbo kbp kbr kbs kca kcb kcc kck kcp kcr kcs kct kkb kkc kkk kkp kkr kks kkt koa kob koc kok koo kop kor kos kot kpa kpc kpk kpo kpp kpr kps kpt kra krc krk kro krp krr krs krt ksa ksb ksc ksk kso ksp ksr kss kst kta ktb ktc ktk kto ktp ktr kts ktt oaa oab oac oak oao oap oar oas oat ob- oba obb obc obk obo obp obr obs obt oc- oca ocb occ ock oco ocp ocr ocs oct oka okb okc okk oko okp okr oks oo- ooa oob ooc ook ooo oop oor oos oot op- opa opb opc opk opo opp opr ops opt or- ora orb orc ork oro orp orr ors ort os- osa osb osc osk oso osp osr oss ost ot- ota otb otc otk oto otp otr ots ott p-p paa pab pac pak pao pap par pas pat pba pbb pbc pbk pbo pbp pbr pbs pbt pca pcb pcc pck pco pcp pcr pcs pct pka pkb pkc pko pkp pkr pks pkt poa pob poc pok poo pop por pos pot ppa ppb ppc ppk ppo ppp ppr pps ppt pra prb prc prk pro prp prr prs prt ps- psa psb psc psk pso psp psr pss pst pt- pta ptb ptc ptk pto ptp ptr pts ptt ra- raa rab rac rak rao rap rar ras rat rba rbb rbc rbk rbo rbp rbr rbs rbt rca rcb rcc rco rcp rcr rcs rct rkb rkc rkk rko rkp rks rkt roa rob roc rok roo rop ror ros rot rpa rpb rpc rpk rpo rpp rpr rps rpt rra rrb rrc rrk rrp rrr rrs rrt rsa rsb rsc rsk rso rsp rsr rss rst rta rtb rtc rtk rto rtp rtr rts rtt saa sab sac sak sao sap sar sas sat sba sbb sbc sbk sbo sbp sbr sbs sbt sca scb scc sck sco scp scr scs sct sk- ska skb skc skk sko skp skr sks skt soa sob soc sok soo sop sor sos sot spa spb spc spk spo spp spr sps spt sr- sra srb src srk sro srp srr srs srt ss- ssa ssb ssc ssk sso ssp ssr sss sst sta stb stc stk sto stp str sts stt taa tab tac tak tao tap tar tas tat tba tbb tbc tbk tbo tbp tbr tbs tbt tca tcb tcc tck tco tcp tcr tcs tct tka tkb tkc tkk tko tkp tkr tks tkt to- toa tob toc tok too top tor tos tot tpa tpb tpc tpk tpo tpp tpr tps tpt tra trb trc trk tro trp trr trs trt tsa tsb tsc tsk tso tsp tsr tss tst tta ttb ttc ttk tto ttp ttr tts ttt