a-a a-b a-t aaa aab aae aak aam aao aas aat ab- aba abb abe abk abm abo abs abt aea aeb aee aek aem aeo aes aet aka akb ake akk akm ako aks ama amb ame amk amm amo ams amt aoa aob aoe aok aom aoo aos aot as- asa asb ase ask asm aso ass ast at- ata atb ate atm ato ats att baa bab bae bak bam bao bas bat bba bbb bbe bbk bbm bbo bbs bbt be- bea beb bee bek bem beo bes bet bka bkb bke bkk bkm bko bks bkt bma bmb bme bmk bmm bmo bms bmt boa bob boe bok bom boo bos bot bsa bsb bse bsk bsm bso bss bst bta btb bte btk btm bto bts btt eaa eab eae eak eam eao eas eat eba ebb ebe ebk ebm ebo ebs ebt eea eeb eee eek eem eeo ees eet eka ekb eke eko eks ekt em- ema emb eme emk emm emo ems emt eo- eoa eob eoe eok eom eoo eos eot es- esa esb ese esk esm eso ess est eta etb ete etk etm eto ets ett k-t ka- kaa kab kae kak kam kao kas kat kba kbb kbe kbk kbm kbo kbs ke- kea keb kee kek kem keo kes ket kkb kke kkk kkm kks kkt kma kmb kme kmk kmm kmo kms kmt koa kob koe kok kom koo kos kot ksa ksb kse ksk ksm kso kss kst kta ktb kte ktk ktm kto kts ktt m-o maa mab mae mak mam mao mas mat mba mbb mbe mbk mbm mbo mbs mbt mea meb mee mek mem meo mes met mka mkb mke mkk mkm mko mks mkt mma mmb mme mmk mmm mmo mms mmt moa mob moe mok mom moo mos mot msa msb mse msk msm mso mss mst mta mtb mte mtk mtm mto mts mtt oaa oab oae oak oam oao oas oat ob- oba obb obe obk obm obo obs obt oea oeb oee oem oeo oes oet oka okb oke okk oko oks om- oma omb ome omm omo oms omt oo- ooa oob ook oom ooo oos oot os- osa osb ose osk osm oso oss ost ot- ota otb ote otk otm oto ots ott saa sab sae sak sam sao sas sat sba sbb sbe sbk sbm sbo sbs sbt se- sea seb see sek sem seo ses set sk- ska skb ske skk skm sko sks skt sma smb sme smk smm smo sms smt soa sob soe sok som soo sos sot ss- ssa ssb sse ssk ssm sso sss sst sta stb ste stk stm sto sts stt taa tab tae tak tam tao tas tat tba tbb tbe tbk tbm tbo tbs tbt te- tea teb tee tek tem teo tes tet tka tkb tke tkk tkm tko tks tkt tma tmb tme tmk tmm tmo tms tmt to- toa tob toe tok tom too tos tot tsa tsb tse tsk tsm tso tss tst tta ttb tte ttk ttm tto tts ttt