recc rece rech recp recr recu reeb reen reep rehb rehe rehn rene renn reno renu reop reou repe repo repp repr repu rere rero reru reue reup reuu rhce rhcp rheb rhee rhen rheo rhob rhoc rhoh rhon rhue rhun rnbr rnco rncp rob- robb robe robo robu rocc roce roch roco roen roer rohe rohn rohr rohu ronc rone rono roob roon roop roor rope ropo rorc rore roro roru roub roue rouh roun roup rpho rpob rpoe rpon rppn rrrr rrun rubb rube rubp rubu ruce ruch ruen ruer ruhe ruhh ruhn ruhr runc rune runn runo rupe rupp rurc rure ruro rurp ruru ruun u-rp ubbe ubbo uber uboc ubon ubpc ucbc uccp uche ucho ucon ucpb ucph ucrc ueno uher uhno uhoh uhuh uhup unbe uncc unce unch unco uncp uneb unec unee unen uner unne unno unon unop unpc unro uocc uone uor- uore upbe upen upne upnp upon upor uppc uppe uppp uppu upup urbe urch ure- ureh urho urne uro- uroo urpo urre urrh urun urup urur uucp uuen uuno uuoc uuuu