a-a a-b a-c a-t aaa aab aac aad aak aao aar aas aat ab- aba abb abc abd abk abo abr abs abt ac- aca acb acc acd ack aco acr acs act ad- ada adb adc add adk ado adr ads adt aka akb akc akd akk ako akr aks aoa aob aoc aod aok aoo aor aos aot ar- ara arb arc ard ark aro arr ars art as- asa asb asc asd ask aso asr ass ast at- ata atb atc atd ato atr ats att baa bab bac bad bak bao bar bas bat bba bbb bbc bbd bbk bbo bbr bbs bbt bca bcb bcc bcd bck bco bcr bcs bct bda bdb bdc bdd bdk bdo bdr bds bdt bka bkb bkc bkk bko bkr bks bkt boa bob boc bod bok boo bor bos bot bra brb brd brk bro brr brs brt bsa bsb bsc bsd bsk bso bsr bss bst bta btb btc btd btk bto btr bts btt c-- caa cab cac cad cak cao car cas cat cba cbb cbc cbd cbk cbo cbr cbs cbt cca ccb ccc ccd cck cco ccr ccs cct cda cdb cdc cdd cdk cdo cdr cds cdt cka ckb ckc ckd cko cks ckt co- coa cob coc cod cok coo cor cos cot cra crb crc crd crk cro crr crs crt csa csb csc csd csk cso csr css cst cta ctb ctc ctd ctk cto ctr cts ctt daa dab dac dad dak dao dar das dat dba dbb dbc dbd dbk dbo dbr dbs dbt dca dcb dcc dcd dck dco dcr dcs dct dda ddb ddc ddd ddk ddo ddr dds ddt dka dkb dkc dkk dko dkr dks dkt doa dob doc dod dok doo dor dos dot dra drb drc drd drk dro drr drs drt dsa dsb dsc dsd dsk dso dsr dss dst dta dtb dtc dtd dtk dto dtr dts dtt k-t ka- kaa kab kac kad kak kao kar kas kat kba kbb kbc kbd kbk kbo kbr kbs kca kcb kcc kcd kck kcr kcs kct kda kdb kdc kdk kdo kdr kds kdt kkb kkc kkk kkr kks kkt koa kob koc kod kok koo kor kos kot kra krc krd krk kro krr krs krt ksa ksb ksc ksd ksk kso ksr kss kst kta ktb ktc ktk kto ktr kts ktt oaa oab oac oad oak oao oar oas oat ob- oba obb obc obd obk obo obr obs obt oc- oca ocb occ ocd ock oco ocr ocs oct oda odb odc odd odo odr ods odt oka okb okc okd okk oko okr oks oo- ooa oob ooc ood ook ooo oor oos oot or- ora orb orc ord ork oro orr ors ort os- osa osb osc osd osk oso osr oss ost ot- ota otb otc otd otk oto otr ots ott ra- raa rab rac rad rak rao rar ras rat rba rbb rbc rbd rbk rbo rbr rbs rbt rca rcb rcc rcd rco rcr rcs rct rda rdb rdc rdd rdo rdr rds rdt rkb rkc rkk rko rks rkt roa rob roc rod rok roo ror ros rot rra rrb rrc rrd rrk rrr rrs rrt rsa rsb rsc rsd rsk rso rsr rss rst rta rtb rtc rtd rtk rto rtr rts rtt saa sab sac sad sak sao sar sas sat sba sbb sbc sbd sbk sbo sbr sbs sbt sca scb scc scd sck sco scr scs sct sda sdb sdc sdd sdk sdo sdr sds sdt sk- ska skb skc skd skk sko skr sks skt soa sob soc sod sok soo sor sos sot sr- sra srb src srd srk sro srr srs srt ss- ssa ssb ssc ssd ssk sso ssr sss sst sta stb stc std stk sto str sts stt taa tab tac tad tak tao tar tas tat tba tbb tbc tbd tbk tbo tbr tbs tbt tca tcb tcc tcd tck tco tcr tcs tct tda tdb tdc tdd tdk tdo tdr tds tdt tka tkb tkc tkk tko tkr tks tkt to- toa tob toc tod tok too tor tos tot tra trb trc trd trk tro trr trs trt tsa tsb tsc tsd tsk tso tsr tss tst tta ttb ttc ttd ttk tto ttr tts ttt