a-ak aaaa aaab aaaf aaar aaba aabb aafa aafb aaff aaka aara abaa abab abaf abak abar abb- abba abbb abbr abff abra afaa afak afar affa afka afkr afr- afra akaa akar akka akr- akra arab araf arak arar arba arfa arfb arff arka arr- arra arrk arrr baaa baaf baak baar baba babb babr baff bak- baka bakr bar- bara barb barf bark barr bbbb brab braf brak brka brkb brrr f--k faaa faba fafa faff fara farb fark farr fbar ffar ffff ffrr fkab frab frak kaaa kaab kaaf kaak kaar kaba kabb kabf kabr kafa kaff kafr kaka kakk kara karb karf kark karr kbaa kbab kbak kbar kbba kbbb kbbf kbbk kbbr kbfb kbff kbfk kbfr kbkb kbkf kbkk kbkr kbra kbrb kbrf kbrk kfab kfar kfbk kffa kffb kfff kffk kfka kfkb kfra kfrr kkaa kkar kkba kkbb kkbr kkfr kkkk kkrb kkrf kkrk kkrr krab krak krar krba krbb krbk krbr krff krka krkk krkr krrb krrf krrk krrr raab raaf raak raba rabb rabk rafa raff raka rakk rara rarb rarf rark rbaf rbbb rbbr rkkf rrrr