-ey bbb bbc bbe bbk bbo bbs bbt bby bcb bcc bce bck bco bcs bct bcy be- beb bec bee bek beo bes bet bey bkb bkc bke bkk bko bks bkt bob boc boe bok boo bos bot boy bsb bsc bse bsk bso bss bst bsy btb btc bte btk bto bts btt bty by- byc bye byk byo bys byt c-- cbb cbc cbe cbk cbo cbs cbt cby ccb ccc cce cck cco ccs cct ce- ceb cec cee cek ceo ces cet cey ckb ckc cko cks ckt cky co- cob coc coe cok coo cos cot coy csb csc cse csk cso css cst csy ctb ctc cte ctk cto cts ctt cty cyb cyc cye cyk cyo cys cyt ebb ebc ebe ebk ebo ebs ebt eby ec- ecb ecc ece eck eco ecs ect eeb eec eee eek eeo ees eet eey ekb ekc eke eko eks ekt eky eo- eob eoc eoe eok eoo eos eot es- esb esc ese esk eso ess est esy etb etc ete etk eto ets ett ety eyc eye eyo eys eyt k-t kbb kbc kbe kbk kbo kbs kcb kcc kce kck kcs kct ke- keb kec kee kek keo kes ket key kkb kkc kke kkk kks kkt kky kob koc koe kok koo kos kot koy ksb ksc kse ksk kso kss kst ktb ktc kte ktk kto kts ktt kyc kye kyo kys kyt ob- obb obc obe obk obo obs obt oby oc- ocb occ ock oco ocs oct oeb oec oee oeo oes oet oey okb okc oke okk oko oks oo- oob ooc ook ooo oos oot os- osb osc ose osk oso oss ost ot- otb otc ote otk oto ots ott oye oyo oys sbb sbc sbe sbk sbo sbs sbt sby scb scc sce sck sco scs sct se- seb sec see sek seo ses set sey sk- skb skc ske skk sko sks skt sky sob soc soe sok soo sos sot soy ss- ssb ssc sse ssk sso sss sst stb stc ste stk sto sts stt sty sy- syb syc sye syk sys syt tbb tbc tbe tbk tbo tbs tbt tcb tcc tce tck tco tcs tct te- teb tec tee tek teo tes tet tey tkb tkc tke tkk tko tks tkt tky to- tob toc toe tok too tos tot toy tsb tsc tse tsk tso tss tst tsy ttb ttc tte ttk tto tts ttt tty tyc tye tyo tys tyt ybc ybe ybs yby ycc yce yco ycs ycy yeb yec yee yek yeo yes yet yey ykk yob yoc yoe yok yoo yos yot yoy ysb ysc yse ysk yso yss yst ysy ytc yte ytk yto yts ytt yyb yyc yye yys yyt yyy