a-be aaaa aaab aaae aaap aaba aabb aabp aabt aaea aaep aapa aapt aata aatt abaa abab abae abap abat abb- abba abbb abbe abbt abee abet abpa abpp abta aeap aeta aett apap apat apba apea apep apet appa appt apta apte aptt at-t ataa atab atae atap atat atea atee atep atta atte attp baaa baat baba babb babe bapa bape bapp bapt bata bate batt bbbb bbeb bbet beap beat beba bebb bebe beeb beep beet beta bete bett bpea btaa btbp bttb eaba eapp eata eate ebba eeea eeee eeta eete epaa epee eppa eppp epta epte etap etat etee etta ette paap paat paba pabt paea paep papa papb pape papp pata pate patt pbpa peab peap peat peba peep peet pepa pepe peta pete pett ppap pppa pppp ppta pptt ptab taa- taat taba tabb tabe tapa tape tapp tapt tata tatb tate tatt tbta tbtp teat teba teet tepa tepe tepp teta tete tett tpap tppa tppp tpte tptp ttab ttbb tttt