a-a a-b a-c a-t aaa aab aac aad aak aan aao aas aat ab- aba abb abc abd abk abn abo abs abt ac- aca acb acc acd ack acn aco acs act ad- ada adb adc add adk adn ado ads adt aka akb akc akd akk akn ako aks an- ana anb anc and ank ann ano ans ant aoa aob aoc aod aok aon aoo aos aot as- asa asb asc asd ask asn aso ass ast at- ata atb atc atd atn ato ats att baa bab bac bad bak ban bao bas bat bba bbb bbc bbd bbk bbn bbo bbs bbt bca bcb bcc bcd bck bcn bco bcs bct bda bdb bdc bdd bdk bdo bds bdt bka bkb bkc bkk bkn bko bks bkt bna bnb bnc bnd bnk bnn bno bns bnt boa bob boc bod bok bon boo bos bot bsa bsb bsc bsd bsk bsn bso bss bst bta btb btc btd btk btn bto bts btt c-- caa cab cac cad cak can cao cas cat cba cbb cbc cbd cbk cbn cbo cbs cbt cca ccb ccc ccd cck ccn cco ccs cct cda cdb cdc cdd cdk cdn cdo cds cdt cka ckb ckc ckd cko cks ckt cn- cna cnb cnc cnd cnn cno cns cnt co- coa cob coc cod cok con coo cos cot csa csb csc csd csk csn cso css cst cta ctb ctc ctd ctk ctn cto cts ctt daa dab dac dad dak dan dao das dat dba dbb dbc dbd dbk dbn dbo dbs dbt dca dcb dcc dcd dck dcn dco dcs dct dda ddb ddc ddd ddk ddn ddo dds ddt dka dkb dkc dkk dko dks dkt dna dnb dnc dnd dnk dnn dno dns dnt doa dob doc dod dok don doo dos dot dsa dsb dsc dsd dsk dsn dso dss dst dta dtb dtc dtd dtk dtn dto dts dtt k-t ka- kaa kab kac kad kak kan kao kas kat kba kbb kbc kbd kbk kbn kbo kbs kca kcb kcc kcd kck kcn kcs kct kda kdb kdc kdk kdo kds kdt kkb kkc kkk kkn kks kkt kn- kna knc knd knk knn kno knt koa kob koc kod kok kon koo kos kot ksa ksb ksc ksd ksk ksn kso kss kst kta ktb ktc ktk ktn kto kts ktt naa nab nac nad nak nan nao nas nat nba nbb nbc nbd nbk nbn nbo nbs nbt nca ncb ncc ncd nck ncn nco ncs nct nda ndb ndc ndd ndk ndn ndo nds ndt nka nkc nkk nkn nko nks nkt nna nnb nnc nnk nnn nno nns nnt no- noa nob noc nod nok non noo nos not nsa nsb nsc nsd nsk nsn nso nss nst nta ntb ntc ntd ntk ntn nto nts ntt oaa oab oac oad oak oan oao oas oat ob- oba obb obc obd obk obn obo obs obt oc- oca ocb occ ocd ock ocn oco ocs oct oda odb odc odd odn odo ods odt oka okb okc okd okk oko oks on- ona onb onc ond onk onn ono ons ont oo- ooa oob ooc ood ook oon ooo oos oot os- osa osb osc osd osk osn oso oss ost ot- ota otb otc otd otk otn oto ots ott saa sab sac sad sak san sao sas sat sba sbb sbc sbd sbk sbn sbo sbs sbt sca scb scc scd sck scn sco scs sct sda sdb sdc sdd sdk sdn sdo sds sdt sk- ska skb skc skd skk sko sks skt sna snb snc snd snk snn sno sns snt soa sob soc sod sok son soo sos sot ss- ssa ssb ssc ssd ssk ssn sso sss sst sta stb stc std stk stn sto sts stt taa tab tac tad tak tan tao tas tat tba tbb tbc tbd tbk tbn tbo tbs tbt tca tcb tcc tcd tck tcn tco tcs tct tda tdb tdc tdd tdk tdn tdo tds tdt tka tkb tkc tkk tko tks tkt tna tnb tnc tnd tnk tnn tno tns tnt to- toa tob toc tod tok ton too tos tot tsa tsb tsc tsd tsk tsn tso tss tst tta ttb ttc ttd ttk ttn tto tts ttt