bbbb bbbs bbdd bd-r bdii bdsd bibb bibi bibs bidi bidr bids bidu biis birb bird biri birr birs birt biru bis- bisd biss bist bisu bitd bits bitt bitu brds brdt brid bris brit brrr brrs brsb brsr brst brud brus brut bsbd bsrd bssd bsts btdt btrt btss bttb btus bubb bubi bubs bubu budb budd budi buds budu buid buir buis buit buiu bur- burb burd buri burr burs burt buru busi buss bust busu but- buti buts butt buus dbit dbrs dbss dbtt dbus dddd ddss ddts ddub dibb dibs didi dids didu diii diis dird dirr dirs dirt dis- disd disi diss dist diti dits ditt dius drib drit drrs drub drui drus drut druu dsdr dsri dsrr dssi dsst dsts dtss dub- dubb dubs dubu dudd duds dudu duid duir duis duit duri durt duru dusi dust duts duur duut ibid ibis ibrd ibri ibss ibtb ibts ibus idid idir idis idss idts idub idus iiii iiis iiit iirs iisd iisi iisr iist iisu iitr iitt irds iri- irid iris irri irrs irti irts irus isbd isbt isdb isds isis isit isri issi issr isss issu istd isti istr ists isus itbs itis itri itrs itsi itsu itur iuds iuiu iusd iuss iust rbbb rbbr rbbs rbds rbis rbsd rbss rbst rib- ribs ribu ridd ridi rids riis riri rirs risd risi riss rist risu riti rits ritt ritu rius rrrr rsbi rsdd rsds rsid rsis rsts rstu rtdt rtss rtts rubb rubi rubs rubu rudd rudi ruds ruid ruis ruit rurd ruri rurs ruru rusi russ rust rusu ruti ruts rutt rutu ruud s-ib s-ii sbbs sbds sbsd sbsi sbst sbus sdds sdib sdrs sdss sdsu sibi sibs sibu sidd sidi sidr sids siit siri sirr sirs sirt siru sisd sisi siss sist sisu sit- sitd siti sits sitt situ siui sius siut srib sris srsd srtr srub ssbr ssdd ssid ssis ssit ssri ssrs sssb sssi ssss sstb sstd ssts stbd stbs stds stib stid stir stis stit strd stri strs stru stsi stss sttd sttr stub stud stur stus stut sub- subb subd subi subs sudd sudi suds suid suir suis suit sur- surd suri surr surs surt suru sus- susd susi suss sust susu suti sutu suus tbbs tbit tbrb tbst tddb tdis tdri tdss tibi tibs tibu tidd tids tiit tiiu tirb tird tiri tirr tirs tiru tisb tisi tiss tist titi tits titt titu tri- trib tris trit trsd trsi trst trtr trub trud trus trut truu tsbd tsdb tsid tsis tssi tssr tsst tsts tsui ttbb ttss tttt tubb tubr tubs tubu tudi tudu tuis tuit tuiu turb turd turi turr turs turt turu tusd tusi tuss tust tuti tuts tutt tutu ubbi ubid ubii ubir ubis ubit ubud uddi udds udid udir udsd udts uirr uisd uist uits urbi urbs urds urdu urib uris uriu urri ursi urss ursu urts urur urus urut usbr usbs usds usdt usis ussb ussr usss usst ussu ustb usti usts usui usus utid utis utri utti uttu uuri uusi uuuu