-er -ey bbb bbc bbe bbk bbo bbr bbs bby bcb bcc bce bck bco bcr bcs bcy be- beb bec bee bek beo ber bes bey bkb bkc bke bkk bko bkr bks bob boc boe bok boo bor bos boy brb bre brk bro brr brs bry bsb bsc bse bsk bso bsr bss bsy by- byc bye byk byo byr bys c-- cbb cbc cbe cbk cbo cbr cbs cby ccb ccc cce cck cco ccr ccs ce- ceb cec cee cek ceo cer ces cey ckb ckc cko cks cky co- cob coc coe cok coo cor cos coy crb crc cre crk cro crr crs cry csb csc cse csk cso csr css csy cyb cyc cye cyk cyo cyr cys ebb ebc ebe ebk ebo ebr ebs eby ec- ecb ecc ece eck eco ecr ecs eeb eec eee eek eeo eer ees eey ekb ekc eke eko ekr eks eky eo- eob eoc eoe eok eoo eor eos erb erc ere erk ero err ers ery es- esb esc ese esk eso esr ess esy eyc eye eyo eyr eys kbb kbc kbe kbk kbo kbr kbs kcb kcc kce kck kcr kcs ke- keb kec kee kek keo ker kes key kkb kkc kke kkk kkr kks kky kob koc koe kok koo kor kos koy krc krk kro krr krs kry ksb ksc kse ksk kso ksr kss kyc kye kyo kyr kys ob- obb obc obe obk obo obr obs oby oc- ocb occ ock oco ocr ocs oeb oec oee oeo oer oes oey okb okc oke okk oko okr oks oo- oob ooc ook ooo oor oos or- orb orc ore ork oro orr ors ory os- osb osc ose osk oso osr oss oye oyo oys rbb rbc rbe rbk rbo rbr rbs rcb rcc rce rco rcr rcs re- reb rec ree rek reo rer res rey rkb rkc rke rkk rko rks rky rob roc roe rok roo ror ros roy rrb rrc rrk rrr rrs rsb rsc rse rsk rso rsr rss ry- ryc rye ryk ryo ryr rys ryy sbb sbc sbe sbk sbo sbr sbs sby scb scc sce sck sco scr scs se- seb sec see sek seo ser ses sey sk- skb skc ske skk sko skr sks sky sob soc soe sok soo sor sos soy sr- srb src sre srk sro srr srs sry ss- ssb ssc sse ssk sso ssr sss sy- syb syc sye syk syr sys ybc ybe ybr ybs yby ycc yce yco ycs ycy yeb yec yee yek yeo yer yes yey ykk yob yoc yoe yok yoo yor yos yoy yrc yre yro yrs ysb ysc yse ysk yso ysr yss ysy yyb yyc yye yys yyy