a-ak a-be aaaa aaab aaae aaap aaba aabb aabp aaea aaep aaka aake aapa abaa abab abae abak abap abb- abba abbb abbe abee abpa abpp aeap aeka akaa akae akap akee akka apak apap apba apea apep apke appa 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 kaaa kaab kaak kaap kaba kabb kabe kaep kaka kake kakk kap- kapa kape kapp kbaa kbab kbae kbak kbap kbba kbbb kbbe kbbk kbeb kbee kbek kbkb kbkk kbpa kbpe kbpk kea- keak keap keba kebb kebe keek keep keka kekb keke kep- kepa kepe kkaa kkap kkba kkbb kkbe kkea kkkk kkpk kpae kpak kpba kpbb kpbe kpek kpke kpkk kppk kppp paak paap paba paea paep paka pake papa papb pape papp pbpa pbpk peab peak peap peba peek peep peka peke pekk pepa pepe ppap pppa pppp