bbbb bbci bbrc bcbc bccc bcci bcru bcuc bibb bibi bicc bici bick biku birb biri birk birr biru brcb bric brik brkb brrr bruc bubb bubi bubu bucc buci buck bucu buic buik buir buiu buki bukk buku bur- burb buri burk burr buru cbbc cbcc cbcr cbcu cbir cbkr ccbc cccb cccc ccci cccu ccic ccii ccir ccrc ccri ccuc cibc cibi cicc cici cicr cicu ciii cikr cirb circ ciri cirk cirr ciuc ckbc ckbi ckck ckrc crbc crbu crcc crcr crib cric crik criu crkc crub cruk cub- cubb cubi cucc cuci cuck cui- cuir cuk- curb curi curr ibrc ibri icbc iccb iccc icci iccr iccu icrc icrr icru icub iiii iirc iiuc ikki ikri ircc ircu iri- iric irki irrc irri iucc iuiu k-ci kbbb kbbc kbbi kbbk kbbr kbbu kbcb kbci kbck kbcr kbcu kbib kbic kbik kbiu kbkb kbkk kbkr kbrb kbrc kbri kbrk kbru kbub kbuc kbuk kbur kbuu kcbc kcbi kcbk kcbr kcbu kccb kccc kcci kcck kccr kccu kcic kcii kcir kciu kckc kckk kckr kcrc kcri kcrr kcru kcub kcui kcuk kibb kibc kibi kibr kibu kicb kicc kick kicr kiic kiii kiik kiiu kikc kiki kikk kikr kiku kirb kirc kiri kirk kirr kiru kiur kiuu kkbb kkbi kkbr kkcb kkci kkck kkcr kkic kkik kkkk kkrb kkrc kkrk kkrr kkuu krbb krbi krbk krbr krcb krcc krci krcu krib krik krkc krki krkk krkr krku krrb krrc krri krrk krrr kruc krui kruk krur kubb kubc kubr kubu kucb kucc kuci kucr kuic kuik kuki kukk kuku kurb kuri kurk kurr kuru kuub kuuk kuur kuuu rbbb rbbr rcbc rccb rccc rcic rib- ribu ricc rick riki rikk riku riri rrrr rubb rubi rubu ruci ruck ruki rukk ruku rurc ruri ruru ubbi ubic ubii ubik ubir ucbc ucci ucrc uirr ukcc ukrc ukur urbi urci urib uric urik uriu urri uruk urur uuri uuuu