b-u bbb bbd bbk bbo bbs bbu bby bdb bdd bdk bdo bds bdu bdv bdy bkb bkk bko bks bkv bob bod bok boo bos bou bov boy bsb bsd bsk bso bss bsu bsv bsy bub bud buk buo bus buu buy bvb bvd bvk bvo bvs bvu bvv by- byd byk byo bys byu dbb dbd dbk dbo dbs dbu dbv dby ddb ddd ddk ddo dds ddu ddy dkb dkk dko dks dku dob dod dok doo dos dou dov doy dsb dsd dsk dso dss dsu dsv dsy dub dud duk duo dus duv duy dvb dvd dvk dvs dvu dy- dyb dyd dyk dyo dys dyu dyy kbb kbd kbk kbo kbs kbu kdb kdk kdo kds kdu kdy kkb kkk kks kku kkv kky kob kod kok koo kos kou koy ksb ksd ksk kso kss ksu ksv kub kud kuk kus kuu kuy kvb kvk kvo kvs kvv kyd kyo kys kyu ob- obb obd obk obo obs obu obv oby odb odd odo ods odu odv okb okd okk oko oks oku oo- oob ood ook ooo oos oov os- osb osd osk oso oss osu osv ou- oud ouk ouo ous ov- ovb ovd ovo ovs ovv oyd oyo oys sbb sbd sbk sbo sbs sbu sbv sby sdb sdd sdk sdo sds sdu sdv sdy sk- skb skd skk sko sks sku sky sob sod sok soo sos sou sov soy ss- ssb ssd ssk sso sss ssu ssv sub sud suk suo sus suu suv suy svb svd svk svo svs svu svv svy sy- syb syd syk sys syu ubb ubk ubo ubs ubu ubv uby udb udd udk udo uds udu udv ukb ukk uku uob uod uok uoo uos usb usd usk uso uss usu usv uus uuu uvb uvo uvs uvu uvv uyo uys uyu vbd vbk vbo vbs vbv vdb vdd vdk vdo vds vdu vdv vkb vob vod vok voo vos vou vov voy vsb vsd vsk vso vss vsu vsv vuk vus vuv vvb vvo vvs vvv vyd ybs yby ydo yds ydy ykk yob yod yok yoo yos you yoy ysb ysk yso yss ysu ysy yud yuk yuo yus yuu yuv yuy yvo yvy yyb yys yyu yyy