prob proc prom pron proo prop prou prri prrm prum pruu pubu puin puir puiu pumi pump punc puno punu pupi pupu pur- purb puri puro purp purr puru puuc rbbb rbbr rcbc rcbo rccb rccc rcic rcmp rcnr rcon rcpi rcpo rib- ribo ribu ricc rico riin rimi rimm rimo rimu rinn rino riom rion riou ripi ripp ripr riri rmon rmrp rnbr rnco rncp rnin rob- robb robi robo robu rocc roco roin roio roir roiu romb romi romm romo romp ronc roni rono roob rooi room roon roop roor ropo rorc rori roro roru roub roum roun roup rpii rpob rpon rppn rrmc rrmp rrrr rrum rrun rubb rubi rubp rubu ruci ruin rumb rumi rumm rumo rump runc runi runn runo rupp rurc ruri ruro rurp ruru ruun u-rp ubbi ubbo ubic ubii ubir uboc ubon ubpc ucbc ucci uccp ucin ucio ucmc ucom ucon ucpb ucrc uipi uirr umb- umbi umbo ummo umno umor umpc umri uncc unci unco uncp uni- unic unii unin unio unir unmc unmr unni unno unon unop unpc unro unum uocc uomo uor- upci upic upim upin upmc upnp upon upor uppc uppp uppu upri upup urbi urci urib uric urim urin uriu urmi urni uro- urom uroo urpo urri urum urun urup urur uucp uuni uuno uuoc uuri uuuu