f--k ffff ffrr ffss fofo foof fook foos for- fork foro forr fors foso foss fros frso fsfo fssf k-os kfff kffk kfok kfoo kfor kfro kfrr kfrs kfsk kfsr kkfr kkfs kkkk kkoo kkor kkrf kkrk kkro kkrr kkrs kksf kksr kkss koff kofk kofo kokf kokk koko kokr koks kook kooo koor koos korf kork koro korr kors kos- kosf koso kosr koss krff krfo krfs krkk krko krkr krks krof krok kroo kror kros krrf krrk krro krrr krrs krsf krsk krsr krss ksfo ksfr kskf kskk ksko kskr ksks ksof ksok ksoo ksor ksos ksrf ksro ksrr ksrs ksso kssr ksss off- offo offr offs ofor okko okok okor okro okso ooff oofs oooo ooos orff orfs orko oro- orof orok oror oros orro orrs orsk orso osoo osor osos osro osso rkkf rkos rkss roff rofo rokk roko rokr roks roof rook roor roos rork roro roso ross rrrr rsos s-os sfor sfos sfro sfss skor skss sofo sokk soko soof sook soor soos soro sorr sors soso soss sros ssrs sssf ssss