-th a-a a-b a-c a-t aaa aab aac aah aak aao aas aat ab- aba abb abc abh abk abo abs abt ac- aca acb acc ach ack aco acs act aha ahb ahc ahh ahk aho ahs aht aka akb akc akh akk ako aks aoa aob aoc aoh aok aoo aos aot as- asa asb asc ash ask aso ass ast at- ata atb atc ath ato ats att baa bab bac bah bak bao bas bat bba bbb bbc bbh bbk bbo bbs bbt bca bcb bcc bch bck bco bcs bct bha bhb bhc bhh bhk bho bhs bht bka bkb bkc bkk bko bks bkt boa bob boc boh bok boo bos bot bsa bsb bsc bsh bsk bso bss bst bta btb btc bth btk bto bts btt c-- caa cab cac cah cak cao cas cat cba cbb cbc cbh cbk cbo cbs cbt cca ccb ccc cch cck cco ccs cct ch- cha chb chc chh chk cho chs cht cka ckb ckc ckh cko cks ckt co- coa cob coc coh cok coo cos cot csa csb csc csh csk cso css cst cta ctb ctc cth ctk cto cts ctt haa hab hac hah hak hao has hat hba hbb hbc hbh hbk hbo hbs hbt hca hcb hcc hch hck hco hcs hct hha hhb hhc hhh hhk hho hhs hht hka hkb hkh hkk hko hks hkt hoa hob hoc hoh hok hoo hos hot hsa hsb hsc hsh hsk hss hst hta htb htc hth htk hto hts htt k-t ka- kaa kab kac kah kak kao kas kat kba kbb kbc kbh kbk kbo kbs kca kcb kcc kch kck kcs kct kha khh khk kho khs kkb kkc kkh kkk kks kkt koa kob koc koh kok koo kos kot ksa ksb ksc ksh ksk kso kss kst kta ktb ktc kth ktk kto kts ktt oaa oab oac oah oak oao oas oat ob- oba obb obc obh obk obo obs obt oc- oca ocb occ och ock oco ocs oct oha ohc ohh oho ohs oht oka okb okc okk oko oks oo- ooa oob ooc ooh ook ooo oos oot os- osa osb osc osh osk oso oss ost ot- ota otb otc oth otk oto ots ott saa sab sac sah sak sao sas sat sba sbb sbc sbh sbk sbo sbs sbt sca scb scc sch sck sco scs sct sh- sha shb shc shh shk sho shs sht sk- ska skb skc skh skk sko sks skt soa sob soc soh sok soo sos sot ss- ssa ssb ssc ssh ssk sso sss sst sta stb stc sth stk sto sts stt taa tab tac tah tak tao tas tat tba tbb tbc tbh tbk tbo tbs tbt tca tcb tcc tch tck tco tcs tct th- tha thb thc thh thk tho ths tht tka tkb tkc tkk tko tks tkt to- toa tob toc toh tok too tos tot tsa tsb tsc tsh tsk tso tss tst tta ttb ttc tth ttk tto tts ttt