a-a a-b a-c a-t aaa aab aac aad aak aao aas aat ab- aba abb abc abd abk abo abs abt ac- aca acb acc acd ack aco acs act ad- ada adb adc add adk ado ads adt aka akb akc akd akk ako aks aoa aob aoc aod aok aoo aos aot as- asa asb asc asd ask aso ass ast at- ata atb atc atd ato ats att baa bab bac bad bak bao bas bat bba bbb bbc bbd bbk bbo bbs bbt bca bcb bcc bcd bck bco bcs bct bda bdb bdc bdd bdk bdo bds bdt bka bkb bkc bkk bko bks bkt boa bob boc bod bok boo bos bot bsa bsb bsc bsd bsk bso bss bst bta btb btc btd btk bto bts btt c-- caa cab cac cad cak cao cas cat cba cbb cbc cbd cbk cbo cbs cbt cca ccb ccc ccd cck cco ccs cct cda cdb cdc cdd cdk cdo cds cdt cka ckb ckc ckd cko cks ckt co- coa cob coc cod cok coo cos cot csa csb csc csd csk cso css cst cta ctb ctc ctd ctk cto cts ctt daa dab dac dad dak dao das dat dba dbb dbc dbd dbk dbo dbs dbt dca dcb dcc dcd dck dco dcs dct dda ddb ddc ddd ddk ddo dds ddt dka dkb dkc dkk dko dks dkt doa dob doc dod dok doo dos dot dsa dsb dsc dsd dsk dso dss dst dta dtb dtc dtd dtk dto dts dtt k-t ka- kaa kab kac kad kak kao kas kat kba kbb kbc kbd kbk kbo kbs kca kcb kcc kcd kck kcs kct kda kdb kdc kdk kdo kds kdt kkb kkc kkk kks kkt koa kob koc kod kok koo kos kot ksa ksb ksc ksd ksk kso kss kst kta ktb ktc ktk kto kts ktt oaa oab oac oad oak oao oas oat ob- oba obb obc obd obk obo obs obt oc- oca ocb occ ocd ock oco ocs oct oda odb odc odd odo ods odt oka okb okc okd okk oko oks oo- ooa oob ooc ood ook ooo oos oot os- osa osb osc osd osk oso oss ost ot- ota otb otc otd otk oto ots ott saa sab sac sad sak sao sas sat sba sbb sbc sbd sbk sbo sbs sbt sca scb scc scd sck sco scs sct sda sdb sdc sdd sdk sdo sds sdt sk- ska skb skc skd skk sko sks skt soa sob soc sod sok soo sos sot ss- ssa ssb ssc ssd ssk sso sss sst sta stb stc std stk sto sts stt taa tab tac tad tak tao tas tat tba tbb tbc tbd tbk tbo tbs tbt tca tcb tcc tcd tck tco tcs tct tda tdb tdc tdd tdk tdo tds tdt tka tkb tkc tkk tko tks tkt to- toa tob toc tod tok too tos tot tsa tsb tsc tsd tsk tso tss tst tta ttb ttc ttd ttk tto tts ttt