bbbb bbbs bblb bbls blkb blls blss blub blus bubb bubs bubu bukk buku bulb bulk bull buls bulu busk buss busu buus kbbb kbbk kbbl kbbs kbbu kbkb kbkk kbkl kblb kbll kbls kblu kbsb kbsk kbss kbsu kbub kbuk kbul kbus kbuu kkbb kkbl kkbs kkkk kklb kkll kkls kkss kksu kkus kkuu klbb klbl klbs klbu klkk klkl klks kllb kllk klls klsu klub kluk kluu ksbl ksbs kskb kskk ksks ksku kslb kslk ksll kslu kssl ksss kssu ksub ksuu kubb kubs kubu kukk kukl kuks kuku kulb kull kulu kusb kusu kuub kuuk kuul kuuu llbs llks llll lsbu lubs lull lulu lusk luss luuk sbbs sbus skss skul slsu slub sssb ssss sub- subb subl subs suks suku sul- sulk sull sulu sus- susk suss susu suus ubls uluk ulul ulus us-k usbl usbs uslu ussb usss ussu usul usus uulu uuuu