a-be aaaa aaab aaae aaaf aaap aaar aaba aabb aabp aaea aaep aafa aafb aaff aapa aara aare aarp abaa abab abae abaf abap abar abb- abba abbb abbe abbr abee aber abff abpa abpp abpr abra aeaf aeap aeer aer- aera afaa afap afar afee afer affa afpa afpe afr- afra afre apap apar apba apbr apea apep aper apfa appa appr apra apre arab arae araf arap arar arba arbe area aree aref arep arfa arfb arff arpa arpe arr- arra arre arrr baaa baaf baar baba babb babe babr baer baff bapa bape bapp bar- bara barb bare barf barr bbbb bbeb bbpr beaf beap bear beba bebb bebe beeb beef beep beer befa befe beff bera bere berr bfpp bpea brab brae braf brea breb bree bref brep brer brrr eaaf eaba eafb eapp eara earb eare earp ebba ebbr eber eeea eeee eefa eefe eera efab efbr effa efpa epaa epee eper epfa eppa eppp epra eprb eprp eraf erap erba erbb erbe ereb erer erpa erpe erra erre faaa faap faba fabe faeb fafa fafe faff fapa fape fapp fara farb fare farp farr fbar feaf feap fear feba feeb feer fefe feff fepa fera ferb fere ferr ffar ffee ffff ffrr fpaa fpra fprf frab frae frap frea free frep paap paar paba paea paep paer pafa pafe paff papa papb pape papp papr par- para pare parf parp parr pbar pbpa pbrf peab peap pear peba peep peer peff pepa pepe per- pera pere perf perp perr pfaa pfff pffr pfra ppap ppar pper ppfa pppa pppp pprf prae prar pre- preb pree pref prep raab raaf raba rabb rabe raef raep raer rafa rafe raff rapa rape rapp rara rarb rare rarf rbaf rbbb rbbr rea- reae reaf reap rear reba rebb rebe reeb reef reep refe reff refr repe repp repr rera rere rfae rfef rrrr