-ey bbb bbc bbe bbk bbo bbs bby bcb bcc bce bck bco bcs bcy be- beb bec bee bek beo bes bey bkb bkc bke bkk bko bks bob boc boe bok boo bos boy bsb bsc bse bsk bso bss bsy by- byc bye byk byo bys c-- cbb cbc cbe cbk cbo cbs cby ccb ccc cce cck cco ccs ce- ceb cec cee cek ceo ces cey ckb ckc cko cks cky co- cob coc coe cok coo cos coy csb csc cse csk cso css csy cyb cyc cye cyk cyo cys ebb ebc ebe ebk ebo ebs eby ec- ecb ecc ece eck eco ecs eeb eec eee eek eeo ees eey ekb ekc eke eko eks eky eo- eob eoc eoe eok eoo eos es- esb esc ese esk eso ess esy eyc eye eyo eys kbb kbc kbe kbk kbo kbs kcb kcc kce kck kcs ke- keb kec kee kek keo kes key kkb kkc kke kkk kks kky kob koc koe kok koo kos koy ksb ksc kse ksk kso kss kyc kye kyo kys ob- obb obc obe obk obo obs oby oc- ocb occ ock oco ocs oeb oec oee oeo oes oey okb okc oke okk oko oks oo- oob ooc ook ooo oos os- osb osc ose osk oso oss oye oyo oys sbb sbc sbe sbk sbo sbs sby scb scc sce sck sco scs se- seb sec see sek seo ses sey sk- skb skc ske skk sko sks sky sob soc soe sok soo sos soy ss- ssb ssc sse ssk sso sss sy- syb syc sye syk sys ybc ybe ybs yby ycc yce yco ycs ycy yeb yec yee yek yeo yes yey ykk yob yoc yoe yok yoo yos yoy ysb ysc yse ysk yso yss ysy yyb yyc yye yys yyy