f--k ffff ffrr fftf fofo foof fook foot fopp for- fork foro forr fort foto fotp fott fprf frop frot ftop kfff kffk kfok kfoo kfor kfpr kfpt kfro kfrp kfrr kftk kftt kkfr kkft kkkk kkoo kkor kkot kkpk kkpt kkrf kkrk kkro kkrr kkrt kktk koff kofk kofo kofp koft kokf kokk koko kokp kokr kook kooo koop koor koot kopf kopp kopr kopt korf kork koro korr kort kotk koto kotr kott kpfk kpfr kpft kpkk kpkr kpof kpok kpoo kpop kppk kppo kppp kppr kprf kprk kpro kprp kprr kprt kpto kptr kptt krff krfo krfp krft krkk krko krkr krof krok kroo krop kror krpr krpt krrf krrk krro krrr krrt krtk krto krtr ktfo ktkk ktko ktkr ktkt ktok ktoo ktop ktor ktot ktpk ktpo ktpr ktpt ktrf ktrk ktro ktrp ktrr ktrt kttf kttk ktto kttp kttr kttt off- offo offr ofor oftp okko okok okor okot okpo okro okto ooff oooo oort ootp opo- opor oppo opto orff orko oro- orof orok oror orot orro orto otfp oto- otof otok otoo otor otpp otro otto pfff pffr pfft pfkp poff poko poof pook poop poor poot pop- popo popp popt pork poro porr port potf poto pott pppo pppp pprf pptt pro- prof proo prop prot prtp prtr ptop ptrf pttk rkkf roff rofo rokk roko rokr roof rook roop roor root ropo rork roro rort rotk roto rotr rott rpof rrrr rttp tfot tfpt tftp tkof toff tofo toft toko toof took toor toot top- topf topo topp topt torf tork toro torp torr tort toto totr tott tppp tppr tptp tptr trfr troo trop trot trpp trtr ttff ttop tttt