a-be aaaa aaab aaae aaap aaba aabb aabp aabt aaea aaep aaoe aaoo aapa aapo aapt aata aatt abaa abab abae abap abat abb- abba abbb abbe abbo abbt abee abet aboa abob aboo abot abpa abpp abta aeap aeta aeto aett aoba aopo apao apap apat apba apea apep apet apo- apoe apoo apop apot appa appt apta apte aptt at-t ataa atab atae atap atat atea atee ateo atep atob atoe atop atot atta atte atto attp baaa baat baba babb babe babo bapa bape bapp bapt bata bate bato batt bbbb bbeb bbet beap beat beba bebb bebe bebo beeb beep beet beo- beot bepo beta bete beto bett boab boat boba bobb bobe bobo boea boee boeo boep boet boob booe boop boot bopa bope bopp bota botb bote boto bott bpea bpoe bpot btaa btbp btob bttb eaba eaop eapp eata eate ebba ebbo eboe eboo ebpo eeea eeee eeta eete eota eoto epaa epee epot eppa eppo eppp epta epte etap etat etee etoe etta ette etto o-eo oate obba obbo obea obet oboe obot oepa oeta ooaa ooba oobe oooo ootb ootp opap opep opet opo- oppa oppo opto otap otea otee otep oto- otoe otoo otpp otta otte otto paap paat paba pabt paea paep papa papb pape papp pata pate pato patt pbpa peab peap peat peba peep peet pepa pepe pepo peta pete peto pett poat poba pobo poea poet poop poot pop- popa pope popo popp popt pota pote poto pott ppap ppoa pppa pppo pppp ppta pptt ptab ptop taa- taat taba tabb tabe tabo taoa tapa tape tapo tapp tapt tata tatb tate tato tatt tbta tbtp teat teba tebo teet tepa tepe tepp teta tete teto tett toab toat toba tobe tobo tobt toea toee toet tooa toot top- topa tope topo topp topt tota tote toto tott tpap tppa tppp tpte tptp ttab ttbb tteo ttoe ttop tttt