a-wa aaaa aaab aaac aaba aabb aabc aabt aabw aaca aacb aacc aact aata aatc aatt aatw aawt aaww abaa abab abac abat abaw abb- abba abbb abbt abca abcb abcc abct abcw abta abwa ac-t acaa acab acac acat acba acca accc acct acta actc actt acwa acww at-t ataa atab atac atat atca atcc atta atwa atwt awac awwa baaa baat baba babb bac- baca bacc bact bata batc batt baw- bbbb bbwc bcaa bcat bcbc bcca bccc bctc btaa btcc bttb btwc bwaa caaa caab caac caat caba cac- caca cacc cacw cat- cata catb catc catt catw cbac cbat cbbc cbca cbcc cbct cbta cbtc cbwa ccaa ccab ccac ccat ccba ccbc ccca cccb cccc cctb cctc cctt ctab ctba ctca ctta cttw cwac taa- taat taba tabb tabc taca tacc tact tata tatb tatt tawa tawt taww tbca tbcb tbcc tbta tcca tccc tctc ttab ttbb tttt twat twbt waaa waac waat waaw waba wabb wabc wabt wabw waca wacb wacc wact wata watb watc watt watw wawa wawb wawc wawt wbaa wbab wbac wbat wbbb wbbt wbbw wbca wbcb wbct wbcw wbta wbtc wbtt wbtw wbwb wbwc wbwt wcab wcat wcba wcbc wcbt wcbw wcca wccb wccc wcct wccw wcta wctb wctc wctt wctw wcwa wcwb wcwc wtab wtac wtaw wtbb wtbc wtca wtcb wtcc wtct wtcw wtta wttb wttc wttt wttw wtwa wtwb wtwt wtww wwab wwac wwba wwbb wwbc wwbt wwca wwcb wwct wwcw wwta wwtc wwtw wwwa wwwc wwww