a-ak aaaa aaac aaaf aaal aaca aacc aacf aack aacl aafa aafc aaff aafl aaka aala aalc aall acaa acac acca accc accf acfc acfl acla aclc afaa afak afca afcc affa affc afka afla aflc akaa akal akca akka alaa alac alak alal alca alcc alfa alk- alka all- alla alll caaa caac caaf caal cac- caca cacc cack cafa cafc caff cafl caka cala calc calf calk call ccaa ccac ccaf ccca cccc cccf cccl ccfa ccfc ccff ccfl ccla cclc cfaa cfac cfca cfcf cfcl ckac ckck ckcl cklf claf f--k faaa faac faca facc fack fafa fafc faff fala falc falk fall fcal fcca fccf ffcc ffff flac flak flcl kaaa kaaf kaak kaal kacc kacl kafa kafc kaff kaka kakc kakk kala kalc kalf kalk kall kcaa kcac kcal kcca kccc kcck kccl kcfa kcfc kcfl kckc kckf kckk kckl kcla kclc kclf kclk kcll kfac kfal kfcf kffa kfff kffk kfka kfla kflc kflf kfll kkaa kkac kkal kkck kkcl kkkk kklc kklf kkll klaa klac klaf klak klal klca klcc klck klcl klfa klfc klff klka klkc klkk klkl klla kllc kllk laaa laac laak laal laca lacc lack lacl lafc laff laka lala lall lcac lcca lccc lcfc lfca lfcc lkal llcc lllc llll