a-ak aaaa aaab aaac aaar aaba aabb aabc aaca aacb aacc aack aacr aaka aara aarc abaa abab abac abag abak abar abb- abba abbb abbr abca abcb abcc abcr abra abrc acaa acab acac acag acar acba acca accc acga acgr acr- acra acrc acrr agac agag agar agba agca agcc agga agra akaa akar akca akka akr- akra arab arac arag arak arar arba arc- arca arga argb arka arr- arra arrc arrg arrk arrr baaa baak baar baba babb babr bac- baca bacc back baga bagg bak- baka bakr bar- bara barb barc barg bark barr bbbb bbga bbrc bbrg bcaa bcar bcbc bcbg bcca bccc bcra bgca brab brac brag brak brca brcb brka brkb brrr caaa caab caac caba cabg cac- caca cacc cack cacr caga cagg cagr caka cara carb carc cark carr cbac cbar cbbc cbca cbcc cbcr cbga cbgb cbka cbkg cbkr ccaa ccab ccac ccag ccar ccba ccbc ccca cccb cccc ccga ccgc ccra ccrc ccrg cgac cgcc cgcg ckac ckbc ckck ckga ckrc crab crac crag crar crbc crca crcc crcr crkc gaar gaba gabb gabr gack gaga gagg gara garb garg garr gbag gc-c gcaa gcbc gccc gcrg gggg grab grac grbr grcc grrr kaaa kaab kaag kaak kaar kaba kabb kabc kabg kabr kacb kacc kag- kaga kagb kagc kagg kagr kaka kakc kakk kara karb karg kark karr kbaa kbab kbac kbak kbar kbba kbbb kbbc kbbg kbbk kbbr kbca kbcb kbck kbcr kbga kbgb kbgg kbgr kbkb kbkg kbkk kbkr kbra kbrb kbrc kbrg kbrk kcaa kcab kcac kcar kcba kcbc kcbk kcbr kcca kccb kccc kcck kccr kcgc kcgr kckc kckk kckr kcrc kcrg kcrr kgab kgac kgak kgba kgbb kgbc kgbr kgcb kgcc kgcr kgga kggg kggr kgra kgrb kgrc kgrg kgrk kgrr kkaa kkac kkag kkar kkba kkbb kkbg kkbr kkcb kkck kkcr kkgb kkgr kkkk kkrb kkrc kkrk kkrr krab krac krag krak krar krba krbb krbg krbk krbr krca krcb krcc krcg krka krkc krkk krkr krrb krrc krrg krrk krrr raab raag raak raba rabb rabk rac- raca racc rack raga ragg raka rakk rara rarb rark rbbb rbbr rcac rcbc rccb rccc rcga rcgc rcrg rgba rrrr