-th a-a a-c a-t aaa aac aah aao aas aat aax ac- aca acc ach aco acs act acx aha ahc ahh aho ahs aht ahx aoa aoc aoh aoo aos aot aox as- asa asc ash aso ass ast asx at- ata atc ath ato ats att atx ax- axa axh axo axs axt axx c-- caa cac cah cao cas cat cax cca ccc cch cco ccs cct ccx ch- cha chc chh cho chs cht chx co- coa coc coh coo cos cot cox csa csc csh cso css cst csx cta ctc cth cto cts ctt ctx cxc cxh cxo cxs cxt cxx haa hac hah hao has hat hax hca hcc hch hco hcs hct hha hhc hhh hho hhs hht hoa hoc hoh hoo hos hot hox hsa hsc hsh hss hst hsx hta htc hth hto hts htt htx hxc oaa oac oah oao oas oat oax oc- oca occ och oco ocs oct ocx oha ohc ohh oho ohs oht oo- ooa ooc ooh ooo oos oot oox os- osa osc osh oso oss ost osx ot- ota otc oth oto ots ott ox- oxa oxc oxo oxt oxx saa sac sah sao sas sat sax sca scc sch sco scs sct scx sh- sha shc shh sho shs sht soa soc soh soo sos sot sox ss- ssa ssc ssh sso sss sst ssx sta stc sth sto sts stt stx sxc sxs sxt t-x taa tac tah tao tas tat tax tca tcc tch tco tcs tct tcx th- tha thc thh tho ths tht thx to- toa toc toh too tos tot tox tsa tsc tsh tso tss tst tsx tta ttc tth tto tts ttt ttx txs txt xaa xac xas xat xch xcx xht xoa xoc xoo xos xot xox xsa xsc xss xst xtc xts xtx xxo xxx