purb puri purl puro purp purr puru puuc rbbb rbbr rbcl rcbc rcbo rccb rccc rcic rcnl rcnr rcon rcpi rcpo rib- ribo ribu ricc rico riin rill rilo rilp rilu rinn rino riol rion riou ripi ripl ripp ripr riri rlin rnbr rnco rncp rnin rnli rob- robb robi robo robu rocc roco roil roin roio roir roiu roll rolo rolp ronc roni rono roob rooi rool roon roop roor ropo rorc rori roro roru roub roul roun roup rpii rpob rpon rppn rrrr rrun rubb rubi rubp rubu ruci ruin rull rulo runc runi runn runo rupp rurc ruri ruro rurp ruru ruun u-rp ubbi ubbo ubic ubii ubir ubli ublo uboc ubon ubpc ucbc ucci uccp ucil ucin ucio ucon ucpb ucrc uipi uirr ulbc ulcc ulco ulic ulli ullo ullr ulno ulo- uloc ulul uncc unci uncl unco uncp uni- unic unii unin unio unir unlp unni unno unon unop unpc unro uocc uolc uor- upci upic upin uplb uplo upnp upon upor uppc uppp uppu upri upup urbi urci urib uric urin uriu urni uro- urol uroo urpo urri urun urup urur uucp uulu uuni uuno uuoc uuri uuuu