f--k ffff ffrr ffun fnuf fofo fono foof fook foon for- fork forn foro forr foun four fron frou frun fuff fufu fukk fuko fuku funf funk fuor fur- furn furo furr kfff kffk kffn kfnf kfnk kfnn kfno kfok kfon kfoo kfor kfrn kfro kfrr kfru kfun kfuo kkfn kkfr kkkk kknn kkno kknu kkon kkoo kkor kkrf kkrk kkrn kkro kkrr kkuu knfo knfr knkk knnk knnr knok knon knor knou knrk knro knuk knur koff kofk kofo kofu kokf kokk kokn koko kokr koku konk kono kook koon kooo koor koou korf kork korn koro korr koru kour kouu krff krfn krfo krkk krkn krko krkr krku krnk krnn krno krnu krof krok kroo kror krrf krrk krrn krro krrr kruf kruk krun krur kuff kufn kufo kufr kukk kukn kuku kunk kuno kunr kunu kuok kuon kuoo kurk kuro kurr kuru kuuk kuur kuuu nfff nfon nkok nkor nkrf nnnn noko non- nonn nono nonu noo- nook noon nooo noor nor- norf nork norn noro norr noun nour nron nuff nuku nunk nunn nuno nuon nurn nurr nuru nuuk off- offo offr offu ofno ofor okko okno okok okon okor okro okun okur onno onon onor onur ooff ooku oooo orff orfu orko orno oro- orof orok oron oror orro ouff oun- our- ourn ouro ouu- rkkf roff rofo rokk roko rokr roku ronk rono roof rook roon roor rork roro roru rouf rouk roun rrrr rrun ruff rufo rukk rukn ruku runf runk runn runo ruok ruro ruru ruun ufuk ukko ukok ukon ukur unkn unko unno unon unrf unro uofo uor- urff uro- urok uroo uruk urun urur uuno uuuu