a-ya aaaa aaab aaac aaba aabb aabc aabt aaby aaca aacb aacc aact aacy aata aatc aatt abaa abab abac abat abay abb- abba abbb abbt abby abca abcb abcc abct abta abyc abyt abyy ac-t acaa acab acac acat acba acca accc acct accy acta actc actt at-t ataa atab atac atat atay atca atcc atta atty atya ayat ayay ayca ayta ayya baaa baat baba babb baby bac- baca bacc bact bata batc batt baty baya bayt bbay bbbb bcaa bcat bcbc bcca bccc bctc btaa btcc bttb caaa caab caac caat caba caby cac- caca cacc cat- cata catb catc catt caty cbac cbat cbbc cbca cbcc cbct cbta cbtc cbyt ccaa ccab ccac ccat ccba ccbc ccca cccb cccc cctb cctc cctt ctab ctba ctca ctta cya- cyaa cyba cybb cybc cyc- cyca cycb cycc cyt- cyta cytb cyy- cyyc taa- taat taba tabb tabc taby taca tacc tact tacy tata tatb tatt taty taya tayt tayy tbca tbcb tbcc tbta tcby tcca tccc tctc ttab ttbb tttt tyta tytt tyty yaba yacc yacy yata yaya ycab ycat yccc yctc ytay yyyy