-ana aaaa aaab aaac aaaf aaan aaba aabb aabc aaca aacb aacc aacf aacn aafa aafb aafc aaff aana abaa abab abac abaf aban abb- abba abbb abca abcb abcc abcf abcn abff acaa acab acac acan acba acca accc accf acfc afaa afan afca afcb afcc affa affc ana- anaa anab anac anan anba anbb anca ancc anfa anna annb baaa baaf baan baba babb bac- baca bacc bacn bafc baff bana banc bann bbbb bbfc bbfn bcaa bcbc bcca bccc bcfc bfca caaa caab caac caaf caan caba cabf cac- caca cacc cafa cafb cafc caff cana canc cann cbac cbbc cbca cbcc cbcn cbfb cbfc cbna ccaa ccab ccac ccaf ccba ccbc ccbn ccca cccb cccc cccf ccfa ccfc ccff ccna ccnb ccnc ccnf cfaa cfab cfac cfbc cfbn cfca cfcb cfcf cfcn cffb cfnb cnaa cnac cnbc cnfa cnna faaa faac faan faba faca facc fafa fafc faff fana fanc fcab fcba fcca fccf ffcc ffff fnac naaa naab naac naan naba nabc nabf naca nacc nacf nafa nafc naff nan- nana nanb nann nbaa nbaf nbbc nbca nbcc nbfa nbfc ncaa ncac ncba ncbc ncca nccc nccf nccn ncfc ncna ncnc nfaa nfff nnnn