a-ak a-be aaaa aaab aaae aaap aaba aabb aabp aaea aaep aaka aake aapa abaa abab abae abak abap abax abb- abba abbb abbe abee abpa abpp aeap aeka akaa akae akap akee akka apak apap apax apba apea apep apex apke appa appx ba-x baaa baak baba babb babe baek bak- baka bake bapa bape bapp bbbb bbeb beak beap beba bebb bebe beeb beek beep beka beke bpea eaba eapp ebba eeea eeee eeka eeke eka- ekab ekeb ekek ekka ekpe epaa epee eppa eppp epxp exa- kaaa kaab kaak kaap kaba kabb kabe kaep kaka kake kakk kakx kap- kapa kape kapp kaxa kaxe kbaa kbab kbae kbak kbap kbba kbbb kbbe kbbk kbeb kbee kbek kbex kbkb kbkk kbpa kbpe kbpk kbxb kbxx kea- keak keap keba kebb kebe keek keep keka kekb keke kep- kepa kepe kepx kexa kexb kexx kkaa kkap kkba kkbb kkbe kkea kkex kkkk kkpk kkxa kkxk kkxx kpae kpak kpax kpba kpbb kpbe kpbx kpek kpke kpkk kpkx kppk kppp kpxp kxaa kxba kxbx kxea kxex kxkk kxkx kxpa kxpk kxxe kxxk kxxx paak paap paba pabx paea paep paka pake papa papb pape papp pbpa pbpk peab peak peap peax peba peek peep peka peke pekk pepa pepe ppap pppa pppp xbee xeka xexe xpak xpax xxxx