bbbb bbbs bbdd bd-r bdii bdsd bffs bfsi bfsr bfts bftt bibb bibi bibs bidi bidr bids biff bifi biis birb bird biri birr birs birt bis- bisd biss bist bitd bits bitt brds brdt brid bris brit brrr brrs brsb brsr brst bsbd bsff bsfs bsrd bssd bsts btdt btrt btss bttb dbfs dbit dbrs dbss dbtt dddd ddss ddts dfds dfdt dfrf dfri dftr dfts dibb dibs didi dids dif- diff difs diii diis dird dirr dirs dirt dis- disd disi diss dist diti dits ditt drib drif drit drrs dsdr dsif dsri dsrr dssi dsst dsts dtss fbis fbrs fbsd fdst fdti ffff ffii ffrr ffss fftf fibs fidf fids fiff fifi fift fiii firs fisd fisi fiss fist fiti fits fitt frib frid fris frit frsb frst fsfi fssf ftdi ftii ftrs ftsr ibfi ibid ibis ibrd ibri ibsf ibss ibtb ibts idid idir idis idrf idsf idss idts ifbb ifid ifis ifit ifrb ifrf ifri ifsb iiii iiis iiit iirs iisd iisi iisr iist iitr iitt irds iri- irid iris irri irrs irsf irtf irti irts isbd isbt isdb isds isis isit isri issf issi issr isss istd isti istr ists itbs itif itis itrf itri itrs itsf itsi ittf rbbb rbbr rbbs rbds rbis rbsd rbss rbst rfdi rfds rfid rib- ribs ridd ridi rids riff rifs rift riif riis riri rirs risd risi riss rist riti rits ritt rrif rrrr rsbi rsdd rsds rsid rsis rsts rtbf rtdt rtfb rtss rtts s-ib s-ii sbbs sbds sbsd sbsi sbst sdds sdib sdif sdrs sdsf sdss sfss sfts sibi sibs sidd sidi sidr sids siff sifr sift siit sirf siri sirr sirs sirt sisd sisi siss sist sit- sitd siti sits sitt srfi srib sris srsd srtr ssbr ssdd ssdf ssid ssis ssit ssri ssrs sssb sssf sssi ssss sstb sstd ssts stbd stbs stds stib stid stif stir stis stit strd stri strs stsf stsi stss sttd sttr tbbs tbit tbrb tbst tddb tdff tdis tdri tdss tfrs tfsd tfsi tfss tibi tibs tidd tids tiff tift tiit tirb tird tiri tirr tirs tisb tisi tiss tist titi tits titt trfd trfr tri- trib trif tris trit trsd trsi trst trtr tsbd tsdb tsid tsis tssf tssi tssr tsst tsts ttbb ttff ttss tttt