a-ak aaaa aaab aaar aaas aaba aabb aaka aara aars aasa aass abaa abab abak abar abas abb- abba abbb abbr abbs abra abrs abs- absa abss akaa akar akas akka akr- akra aksa arab arak arar aras arba arbs arka arks arr- arra arrk arrr arrs ars- arsa arsk asaa asab asak asar asas asba aska askr asks asra asrs assa assk assr asss baaa baak baar baas baba babb babr babs bak- baka bakr baks bar- bara barb bark barr bars basa bask bass bbas bbbb bbbs brab brak bras brka brkb brrr brrs brsb brsr bsaa bsas bsra kaaa kaab kaak kaar kaas kaba kabb kabr kaka kakk kaks kara karb kark karr kars kas- kasa kasb kask kasr kass kbaa kbab kbak kbar kbas kbba kbbb kbbk kbbr kbbs kbkb kbkk kbkr kbra kbrb kbrk kbsa kbsb kbsk kbsr kbss kkaa kkar kkba kkbb kkbr kkbs kkkk kkrb kkrk kkrr kkrs kksa kksr kkss krab krak krar kras krba krbb krbk krbr krka krkk krkr krks krrb krrk krrr krrs krsa krsk krsr krss ksab ksak ksar ksas ksba ksbr ksbs kska kskb kskk kskr ksks ksra ksrb ksrr ksrs kssa kssr ksss raab raak raas raba rabb rabk rabs raka rakk rara rarb rark rars rasa rask rass rbbb rbbr rbbs rbss rkss rras rrrr rsaa rssa saab saak saar saas saba sabb sabr sabs saka sakb sakk saks sara sark sarr sars sasa sask sass sbaa sbar sbas sbbs sbrk sbsa skab skar skra skss sras ssaa ssab ssas ssbr ssra ssrs sssa sssb ssss