bbbb bbbs bbin bibb bibi bibs biin biis bin- bini binn bins binu birb biri birn birr birs biru bis- biss bisu bnib bnin bnrr bnss brin bris brns brrr brrs brsb brsr brun brus bsin bsns bubb bubi bubs bubu buin buir buis buiu bunb buni bunn buns bunu bur- burb buri burn burr burs buru busi buss busu buus ibis ibns ibri ibsn ibss ibus iiii iiis iirs iisi iisr iisu inis inni innr inns innu inri inrs inss insu inui inun inus iri- irin iris irri irrs irun irus isbn isin isis isri issi issr isss issu isus iuiu iuss n-ii nibi nibs niir niiu nini nins nirs niru nisi niss nisu niur nnnn nnss nsin nsis nsnr nssb nssr nsss nsub nubi nubs nuin nunn nuns nuri nurn nurr nurs nuru nusi nuss nusu rbbb rbbr rbbs rbis rbss rib- ribs ribu riin riis rinn riri rirs risi riss risu rius rnbr rnin rrrr rrun rsbi rsis rsnn rsnr rubb rubi rubs rubu ruin ruis runi runn runs ruri rurs ruru rusi russ rusu ruun s-ib s-ii sbbs sbsi sbus sibi sibs sibu sini sinn sins sinu siri sirr sirs siru sisi siss sisu siui sius snib snir snns snrs snub snur snus srib sris srni srnn srub ssbn ssbr ssin ssis ssns ssri ssrs sssb sssi ssss sub- subb subi subs suin suir suis sun- sunb suni sunn suns sunu sur- suri surn surr surs suru sus- susi suss susu suus ubbi ubii ubir ubis uirr uni- unii unin unir unis unni unns unrs uns- unus urbi urbs urib urin uris uriu urni urns urri ursi urss ursu urun urur urus usbr usbs usin usis usnr usnu ussb ussr usss ussu usui usun usus uuni uuri uusi uuuu