bbbb bbci bbrc bcbc bccc bcci bcru bcuc bibb bibi bicc bici birb biri birr biru brcb bric brrr bruc bubb bubi bubu bucc buci bucu buic buir buiu bur- burb buri burr buru cbbc cbcc cbcr cbcu cbir ccbc cccb cccc ccci cccu ccic ccii ccir ccrc ccri ccuc cibc cibi cicc cici cicr cicu ciii cirb circ ciri cirr ciuc crbc crbu crcc crcr crib cric criu crub cub- cubb cubi cucc cuci cui- cuir curb curi curr ibrc ibri icbc iccb iccc icci iccr iccu icrc icrr icru icub iiii iirc iiuc ircc ircu iri- iric irrc irri iucc iuiu rbbb rbbr rcbc rccb rccc rcic rib- ribu ricc riri rrrr rubb rubi rubu ruci rurc ruri ruru ubbi ubic ubii ubir ucbc ucci ucrc uirr urbi urci urib uric uriu urri urur uuri uuuu