-hou bbbb bhor bhur bhuu bnor bnrr bobb bobo bobu bohn boho bohr bohu bonn bono bonu boob booh boon boor bor- borh born boro borr boru bouh boun bour brno brob broh bron broo bror brou brrr bruh brun bubb bubo bubu buho buhr bunb bunn buno bunu buon bur- burb burh burn buro burr buru hhhh hobo hohn hoho hono honu hoon hoor horn horo horr hour hrob hron hrun hubb hubo huhn huhu hunh huon huor hurn huro hurr huru huub nbbo nhnn nhon nnnn nobo nobu nohn noho non- nonn nono nonu noo- noob noon nooo noor nor- norb norn noro norr nouh noun nour nron nunn nuno nuon nurn nurr nuru obbo obon obor obrh obro obuh ohho ohno ohob ohoh ohrn onno onon onor onur ooho oooh oooo orbb orbo orbu orno oro- oron oror orro orub oun- our- ourn ouro ouu- rbbb rbbr rboh rhob rhoh rhon rhun rnbr rob- robb robo robu rohn rohr rohu rono roob roon roor roro roru roub rouh roun rrrr rrun rubb rubu ruhh ruhn ruhr runn runo ruro ruru ruun ubbo ubon uhno uhoh uhuh unno unon unro uor- urho uro- uroo urrh urun urur uuno uuuu