a-ak aaaa aaac aaaf aaar aaas aaca aacc aacf aack aacr aacs aafa aafc aaff aaka aara aarc aars aasa aasc aasf aass acaa acac acar acas acca accc accf accs acfc acfs acks acr- acra acrc acrr acrs acsa acsc acss afaa afak afar afca afcc afcs affa affc affs afka afkr afr- afra afrc afrs afsa afsc akaa akar akas akca akka akr- akra aksa arac araf arak arar aras arc- arca arcs arfa arfc arff arfs arka arks arr- arra arrc arrk arrr arrs ars- arsa arsc arsk asaa asac asaf asak asar asas asc- asca ascc ascr asfa aska askr asks asra asrc asrs assa assc assk assr asss caaa caac caaf caas cac- caca cacc cack cacr cafa cafc caff cafs caka cara carc carf cark carr cars casa casc cask casr cass ccaa ccac ccaf ccar ccas ccca cccc cccf cccs ccfa ccfc ccff ccra ccrc ccrf ccrs ccsa ccsf ccss cfaa cfac cfar cfca cfcf cfcs cffr cfra cfsa ckac ckck ckcs ckfr ckrc cksa crac craf crar cras crca crcc crcr crfc crfs crkc crsa crss csaa csac csak csar csas cscc cscf cscr cscs csfc csfr cska csks csra csrc csrs cssa cssr f--k faaa faac faas faca facc fack facs fafa fafc faff fara farc fark farr fars fasa fasc fass fcar fcas fcca fccf fcra fcsc ffar ffcc ffff ffrr ffsa ffss frac frak fras frcc frfc frsc fsas fscc fsck fsra fssa fssc fssf kaaa kaaf kaak kaar kaas kacc kacs kafa kafc kaff kafr kafs kaka kakc kakk kaks kara karf kark karr kars kas- kasa kasc kasf kask kasr kass kcaa kcac kcar kcas kcca kccc kcck kccr kcfa kcfc kckc kckf kckk kckr kcrc kcrr kcrs kcsa kcsc kcsf kcsr kcss kfac kfar kfcf kfcr kfcs kffa kfff kffk kfka kfra kfrc kfrr kfrs kfsa kfsk kfsr kkaa kkac kkar kkck kkcr kkcs kkfr kkfs kkkk kkrc kkrf kkrk kkrr kkrs kksa kksf kksr kkss krac krak krar kras krca krcc krcs krfc krff krfs krka krkc krkk krkr krks krrc krrf krrk krrr krrs krsa krsc krsf krsk krsr krss ksac ksaf ksak ksar ksas ksca ksck kscr kscs ksfa ksfc ksfr kska kskf kskk kskr ksks ksra ksrf ksrr ksrs kssa kssr ksss raaf raak raas rac- raca racc rack racs rafa rafc raff raka rakk rara rarf rark rars rasa rasc rask rass rcac rcaf rcas rccc rccs rcfc rcsa rcsc rcss rffc rkkf rkss rras rrfc rrrr rsaa rsaf rscc rscs rsfc rssa sa-c saac saaf saak saar saas saca sacc sack sacr sacs safa safc saff safr saka sakk saks sara sarc sarf sark sarr sars sasa sasc sasf sask sass scaa scac scaf scak scar scas sccc sccs scfa scfc sck- scr- scra scrc scrs scsa scsc scsr sfar sfas sfca sfcc sfcs sffc sfra sfrc sfss skac skaf skar skfc skra skss sraf sras srcc srfc ssaa ssac ssas ssca sscc sscs ssfc ssra ssrc ssrs sssa sssc sssf ssss