-ey bbb bbe bbk bbo bbs bbx bby be- beb bee bek beo bes bex bey bkb bke bkk bko bks bkx bob boe bok boo bos box boy bsb bse bsk bso bss bsx bsy bxb bxo bxx by- bye byk byo bys ebb ebe ebk ebo ebs ebx eby eeb eee eek eeo ees eex eey ekb eke eko eks eky eo- eob eoe eok eoo eos es- esb ese esk eso ess esx esy ex- exe exo exs exx exy eye eyo eys kbb kbe kbk kbo kbs kbx ke- keb kee kek keo kes kex key kkb kke kkk kks kky kob koe kok koo kos koy ksb kse ksk kso kss kxo kxy kye kyo kys kyx ob- obb obe obk obo obs obx oby oeb oee oeo oes oex oey okb oke okk oko oks oo- oob ook ooo oos oox os- osb ose osk oso oss osx ox- oxb oxo oxx oxy oye oyo oys sbb sbe sbk sbo sbs sbx sby se- seb see sek seo ses sex sey sk- skb ske skk sko sks skx sky sob soe sok soo sos sox soy ss- ssb sse ssk sso sss ssx sxs sy- syb sye syk sys syx xbe xbx xee xes xex xkb xke xks xok xoo xos xox xsb xss xxo xxx xxy xyy ybe ybs yby yeb yee yek yeo yes yex yey ykk yob yoe yok yoo yos yox yoy ysb yse ysk yso yss ysy yxe yxy yyb yye yys yyy