a-ak aaaa aaac aaaf aaar aaca aacc aacf aack aacr aafa aafc aaff aaka aara aarc acaa acac acar acca accc accf acfc acr- acra acrc acrr afaa afak afar afca afcc affa affc afka afkr afr- afra afrc akaa akar akca akka akr- akra arac araf arak arar arc- arca arfa arfc arff arka arr- arra arrc arrk arrr caaa caac caaf cac- caca cacc cack cacr cafa cafc caff caka cara carc carf cark carr ccaa ccac ccaf ccar ccca cccc cccf ccfa ccfc ccff ccra ccrc ccrf cfaa cfac cfar cfca cfcf cffr cfra ckac ckck ckfr ckrc crac craf crar crca crcc crcr crfc crkc f--k faaa faac faca facc fack fafa fafc faff fara farc fark farr fcar fcca fccf fcra ffar ffcc ffff ffrr frac frak frcc frfc kaaa kaaf kaak kaar kacc kafa kafc kaff kafr kaka kakc kakk kara karf kark karr kcaa kcac kcar kcca kccc kcck kccr kcfa kcfc kckc kckf kckk kckr kcrc kcrr kfac kfar kfcf kfcr kffa kfff kffk kfka kfra kfrc kfrr kkaa kkac kkar kkck kkcr kkfr kkkk kkrc kkrf kkrk kkrr krac krak krar krca krcc krfc krff krka krkc krkk krkr krrc krrf krrk krrr raaf raak rac- raca racc rack rafa rafc raff raka rakk rara rarf rark rcac rcaf rccc rcfc rffc rkkf rrfc rrrr