bbbb bbbs bbpr bbrc bcbc bcbp bcbs bccc bccs bcpp bcps bcrs bcru bcsc bcss bcuc bcup bpcp bprc bpsu brcb brrr brrs brsb brsr bruc brup brus bscp bscs bspp bspr bssc bsup bubb bubs bubu bucc bucs bucu bupc bups bur- burb burp burr burs buru busc buss busu buus cbbc cbbs cbcc cbcp cbcr cbcs cbcu cbpc cbpp cbsc cbus ccbc cccb cccc cccp cccs cccu ccpp ccpr ccps ccrc ccrp ccrs ccsp ccss ccuc ccup ccus cpbc cpcs cpcu cpps cprs cpsc cpsr cpsu cpus crbc crbu crcc crcr crpc crps crsp crss crub crup crus cscb cscc cscr cscs cspb cspc csps csrc csrs cssr csup csur csus cub- cubb cubs cucc cupp cupr cups curb curr curs cusb cusp cuss cusu pbcc pbrs pbsp pcbc pcbs pccc pccs pcpb pcpp pcps pcrc ppcc ppcs pppp ppps pprc ppru ppss ppur prbc prbs prcc prcp prcs prps prrs prsc prss prus pruu psbr pscu pspp pspr psps psrp pssc pubs pubu pups pupu pur- purb purp purr purs puru puss puuc rbbb rbbr rbbs rbsp rbss rcbc rccb rccc rccs rcps rcsc rcss rpcs rpps rrrr rrsp rscc rscs rspb rsps rubb rubp rubs rubu rupp rurc rurp rurs ruru russ rusu sbbs sbcc sbcs sbsp sbus sccc sccp sccs scpb scps scr- scrc scrs scsc scsr scsu scub scup scur spcc spcs spps sprs spsp spss spur spus srbc srcc srpc srps srsp srub ssbr sscc sscp sscs sspc ssps ssrc ssrs sssb sssc ssss sub- subb subs suc- succ sucr sucs sup- supp supr sups sur- surc surp surr surs suru sus- susp suss susu suus u-rp ubpc ucbc uccp ucpb ucrc ucsb ucsc ucsu upcs uppc uppp uppu upsc upup urbs urss ursu urup urur urus usbc usbr usbs uscc uscs uspc uspp usps ussb ussc ussr usss ussu usus uucp uuuu