bbbb bbbs bibb bibi bibs biis biku birb biri birk birr birs birt biru bis- bisk biss bist bisu bits bitt bitu brik bris brit brkb brrr brrs brsb brsr brst brus brut bskt bsts btrt btss bttb btus bubb bubi bubs bubu buik buir buis buit buiu buki bukk buku bur- burb buri burk burr burs burt buru busi busk buss bust busu but- buti buts butt buus ibis ibri ibss ibtb ibts ibus iiii iiis iiit iirs iisi iisr iist iisu iitr iitt ikki ikri iksu iri- iris irki irks irri irrs irti irts irus isbt isis isit isku isri issi issr isss issu isti istr ists isus itbs itis itri itrs itsi itsu itur iuiu iuss iust kbbb kbbi kbbk kbbr kbbs kbbt kbbu kbib kbik kbis kbit kbiu kbkb kbkk kbkr kbrb kbri kbrk kbrt kbru kbsb kbsi kbsk kbsr kbss kbst kbsu kbtb kbtk kbtr kbts kbtt kbub kbuk kbur kbus kbut kbuu kibb kibi kibr kibs kibt kibu kiii kiik kiis kiit kiiu kiki kikk kikr kikt kiku kirb kiri kirk kirr kirs kirt kiru kisi kisk kisr kiss kist kisu kiti kitr kits kitt kitu kiur kiuu kkbb kkbi kkbr kkbs kkbt kkik kkit kkkk kkrb kkrk kkrr kkrs kkrt kksi kksr kkss kkst kksu kktk kkts kktu kkus kkut kkuu krbb krbi krbk krbr krbt krib krik kris krit krki krkk krkr krks krku krrb krri krrk krrr krrs krrt krsk krsr krss krst krsu krti krtk krtr krts krui kruk krur ksbi ksbr ksbs ksib ksii ksik ksir ksis ksit kskb kskk kskr ksks ksku ksrb ksrr ksrs ksrt kssi kssr ksss ksst kssu kstb ksti kstk kstr ksts kstt kstu ksub ksui ksut ksuu ktbb ktbr ktbt ktbu ktib ktik ktis ktkb ktkk ktkr ktks ktkt ktku ktrb ktri ktrk ktrr ktrs ktrt ktru ktsr ktst ktsu ktti kttk kttr ktts kttt kttu ktub ktui kubb kubr kubs kubu kuik kuki kukk kuks kuku kurb kuri kurk kurr kurs kurt kuru kusb kust kusu kuti kutr kuts kutt kutu kuub kuuk kuur kuuu rbbb rbbr rbbs rbis rbss rbst rib- ribs ribu riis riki rikk riku riri rirs risi risk riss rist risu riti rits ritt ritu rius rkss rkts rrrr rsbi rsis rsts rstu rtss rtts rubb rubi rubs rubu ruis ruit ruki rukk ruku ruri rurs ruru rusi rusk russ rust rusu ruti ruts rutt rutu s-ib s-ii sbbs sbrk sbsi sbst sbtk sbus sibi sibs sibu siik siit siki sikr siks siku siri sirk sirr sirs sirt siru sisi sisk siss sist sisu sit- siti sits sitt situ siui sius siut skik skir skis skit skiu skrt skss skui skur skut srib sris srtr srub ssbr ssis ssit ssri ssrs sssb sssi ssss sstb ssts stbs stib stik stir stis stit stks stri strk strs stru stsi stss sttr stub stuk stur stus stut sub- subb subi subs suir suis suit suki suks suku sur- suri surr surs surt suru sus- susi susk suss sust susu suti sutu suus tbbs tbit tbrb tbst tibi tibs tibu tiit tiiu tiki tiku tirb tiri tirr tirs tiru tisb tisi tiss tist titi tits titt titu tkts tri- trib trik tris trit trsi trst trtr trub truk trus trut truu tsis tsks tssi tssr tsst tsts tsui ttbb ttss tttt tubb tubr tubs tubu tuik tuis tuit tuiu tuks turb turi turk turr turs turt turu tusi tusk tuss tust tuti tuts tutt tutu ubbi ubii ubik ubir ubis ubit uirr uist uits ukur urbi urbs urib urik uris uriu urri ursi urss ursu urts uruk urur urus urut us-k usbr usbs usis ussb ussr usss usst ussu ustb usti usts usui usus utik utis utri utti uttu uuri uusi uuuu