f--k ffff ffps ffrr ffss fofo foof fook foos fopp fops for- fork foro forr fors foso foss fprf frop fros frps frso fsfo fspf fssf fssp k-os kfff kffk kfok kfoo kfor kfpr kfro kfrp kfrr kfrs kfsk kfsp kfsr kkfr kkfs kkkk kkoo kkor kkpk kkps kkrf kkrk kkro kkrr kkrs kksf kksp kksr kkss koff kofk kofo kofp kokf kokk koko kokp kokr koks kook kooo koop koor koos kopf kopp kopr kops korf kork koro korr kors kos- kosf koso kosp kosr koss kpfk kpfr kpkk kpkr kpof kpok kpoo kpop kppk kppo kppp kppr kprf kprk kpro kprp kprr kprs kpsf kpso kpsp krff krfo krfp krfs krkk krko krkr krks krof krok kroo krop kror kros krpr krps krrf krrk krro krrr krrs krsf krsk krsr krss ksfo ksfr kskf kskk ksko kskr ksks ksof ksok ksoo ksop ksor ksos kspk kspo kspr ksps ksrf ksro ksrp ksrr ksrs ksso kssr ksss off- offo offr offs ofor okko okok okor okpo okro okso ooff oofs oooo ooos oops opo- opor opos oppo opps orff orfs orko oro- orof orok oror oros orps orro orrs orsk orso osoo osor osos osro osso pfff pffr pfkp pfps poff poko poof pook poop poor poos pop- popo popp pops pork poro porr pors posk poso poss ppos pppo pppp ppps pprf ppsf ppss prfs pro- prof proo prop pros prps prrs prso prss psfk psfs psos pspp pspr psps psrk psrp psso rkkf rkos rkss roff rofo rokk roko rokr roks roof rook roop roor roos ropo rops rork roro roso rosp ross rpof rpos rpps rrrr rrsp rsos rspk rspo rsps s-os sfor sfos sfro sfss skop skor skpo skss sofo sokk soko soof sook soop soor soos sopo sopp sops soro sorr sors soso soss spfs spkr spok spoo spop spor spos sppf spps spro sprs spso spsp spss sros srps srsp ssfp ssop sspf sspo ssps ssrs sssf ssss