bbbb bbrc bcbc bccc bcor bcru bctc bcuc bobb bobo bobu boco bocu boob booc boor boot bor- boro borr bort boru botb boto bott bour bout brcb brob broc broo bror brot brou brrr brtc bruc brut btcc btob btor btrc btrt bttb bubb bubo bubu bucc buco bucu bur- burb buro burr burt buru but- buto butt c-bo cbbc cbcc cbcr cbct cbcu cbot cbrt cbtc ccbc cccb cccc cccu ccob ccoc ccrc ccrt cctb cctc cctt ccuc ccut cobb cobo cobu coco coct cocu coob coot cor- corb corc coro corr cort cotb cotc coto cott cotu coub cour cout crbc crbu crcc crcr crob croc croo cror crot crrt crtc crub crut ctor ctot ctrc cub- cubb cucc curb curo curr curt cut- cutc cuto cutt obbo obor obot obro ocbc occc occt ocro ocrr oct- octo ocur oocr oooo oort ootb orbb orbo orbu orco oro- oror orot orro ortc orto orub oto- otoo otor otro otto ottu otur oucc our- ouro ourt out- outb outo ouu- rbbb rbbr rcbc rcbo rccb rccc rctc rob- robb robo robt robu rocc roco roob roor root rorc roro rort roru rotc roto rotr rott roub rout rrrr rtcc rubb rubu ruct rurc ruro ruru ruto rutt rutu tbcb tbcc tbrb tccc tccu tctc tobo tobt tobu toco toor toot torc toro torr tort toru totc toto totr tott tour tout trcc troc troo trot trou trtc trtr trub truc trut truu ttbb tttt tubb tubo tubr tubu tucc tuco tuor turb turc turo turr turt turu tuto tutt tutu tuuo ubbo uboc ucbc ucrc ucut uocc uor- uro- uroo urur urut utor utto uttu uuoc uuuu