bbb bbg bbk bbo bbr bbs bgb bgg bgk bgo bgr bgs bkb bkg bkk bko bkr bks bob bog bok boo bor bos brb brg brk bro brr brs bsb bsg bsk bso bsr bss gbg gbk gbo gbr gbs ggb ggg ggo ggr ggs gkb gko gks gob gog gok goo gor gos grb grg grk gro grr grs gsb gsg gsk gso gsr gss kbb kbk kbo kbr kbs kgb kgo kgs kkb kkk kkr kks kob kog kok koo kor kos krg krk kro krr krs ksb ksg ksk kso ksr kss ob- obb obg obk obo obr obs ogg ogo ogs okb okg okk oko okr oks oo- oob oog ook ooo oor oos or- orb org ork oro orr ors os- osb osg osk oso osr oss rbb rbg rbk rbo rbr rbs rgb rgg rgk rgo rgr rgs rkb rkg rkk rko rks rob rog rok roo ror ros rrb rrg rrk rrr rrs rsb rsg rsk rso rsr rss sbb sbg sbk sbo sbr sbs sgb sgg sgk sgo sgr sgs sk- skb skg skk sko skr sks sob sog sok soo sor sos sr- srb srg srk sro srr srs ss- ssb ssg ssk sso ssr sss