aaaa aaab aaaf aaal aaba aabb aabl aabt aafa aafb aaff aafl aala aall aata aatf aatt abaa abab abaf abal abat abb- abba abbb abbt abff abla abta afaa afat affa afft afla afta alaa alal alat alb- alba alfa all- alla alll alta at-l at-t ataa atab atal atat atfb atla atta baaa baaf baal baat baba babb baff baft bala balf ball balt bata batf batt bbbb bblb bffl bfta bftt blaa blab blat blbt btaa btaf btla bttb faaa faba fafa faff fala fall falt fata fatf fatt fbla ffff fftf flab flat ft-l ftlb laaa laal laat laba lafb laff laft lala lall lata latt lfat llat llll ltbf ltbl taa- taaf taal taat taba tabb tabl tafa taff taft tala tall tata tatb tatt tbaf tbta tfal ttab ttbb ttfa ttff tttt