bbbb bbci bbrc bcbc bccc bcci bcit bcru bctc bcuc bibb bibi bicc bici birb biri birr birt biru bitc bitt bitu brcb bric brit brrr brtc bruc brut btcc btrc btrt bttb bubb bubi bubu bucc buci bucu buic buir buit buiu bur- burb buri burr burt buru but- buti butt cbbc cbcc cbcr cbct cbcu cbir cbit cbrt cbtc ccbc cccb cccc ccci cccu ccic ccii ccir ccrc ccri ccrt cctb cctc cctt ccuc ccut cibc cibi cicc cici cicr cict cicu ciii ciit cirb circ ciri cirr cirt citb citi citt citu ciuc crbc crbu crcc crcr crib cric crit criu crrt crtc crub crut ctbi ctic ctrc cub- cubb cubi cucc cuci cui- cuir cuit curb curi curr curt cut- cutc cutt ibrc ibri ibtb ibtc icbc iccb iccc icci iccr icct iccu icrc icrr icrt icru icub iiii iiit iirc iitr iitt iiuc ircc ircu iri- iric irrc irri irti itic itri itur iucc iuiu rbbb rbbr rcbc rccb rccc rcic rctc rcti rib- ribu ricc rict riri riti ritt ritu rrrr rtcc rubb rubi rubu ruci ruct ruit rurc ruri ruru ruti rutt rutu tbcb tbcc tbit tbrb tccc tccu tctc tibi tibu ticc tiit tiiu tirb tiri tirr tiru titc titi titt titu trcc tri- trib tric trit trtc trtr trub truc trut truu ttbb tttt tubb tubr tubu tucc tuit tuiu turb turc turi turr turt turu tuti tutt tutu ubbi ubic ubii ubir ubit ucbc ucci ucrc ucut uirr urbi urci urib uric uriu urri urur urut utri utti uttu uuri uuuu