bbbb bbbs bblb bbls bbpr blls blsp blss blub blup blur blus bpsu brlp brls brrr brrs brsb brsr brup brus bspp bspr bsup bubb bubs bubu bulb bull buls bulu bups bur- burb burl burp burr burs buru buss busu buus lblr lbrs llbs llll llps lppl lprp lpss lrps lrpu lrrr ls-r lsbu lspl lspr lssp lssr lubs lull lulu lupu lurs luss luup pblu pbrs pbsp plbr plpp plss plup plur plus pppp ppps ppru ppss ppur prbs prlr prls prps prrs prsl prss prus pruu psbr pspp pspr psps psrp publ pubs pubu pull pulp puls pulu pupl pups pupu pur- purb purl purp purr purs puru puss rbbb rbbr rbbs rbsl rbsp rbss rlls rpls rpps rrrr rrsp rslp rspb rsps rssl rubb rubp rubs rubu rull rupp rurp rurs ruru russ rusu sbbs sbsp sbus slbp sllp slpp slps slrp slrs slsu slub slup slur splp splr spls spps sprs spsp spss spur spus srps srsp srub ssbr sslp sspl ssps ssrl ssrs sssb ssss sub- subb subl subs sul- sull sulp sulu sup- supp supr sups sur- surp surr surs suru sus- susp suss susu suus u-rp ubls ullr ulul ulus uplb uppp uppu upup urbs urls urss ursu urup urur urus usbl usbr usbs uslp uslu uspp usps ussb ussr usss ussu usul usus uulu uuuu