aaaa aaab aaac aaad aaar aaba aabb aabc aabd aaca aacb aacc aacd aacr aada aadc aara aarc aard abaa abab abac abad abar abb- abba abbb abbr abca abcb abcc abcd abcr abda abra abrc acaa acab acac acad acar acba acca accc accd acda acdb acdc acr- acra acrc acrr adaa adab adac adad adar adba adbc adcc adda addc addd addr adra arab arac arad arar arba arc- arca arda ardc arr- arra arrc arrr baaa baad baar baba babb babr bac- baca bacc bada badb badd badr bar- bara barb barc bard barr bbad bbbb bbdd bbrc bcaa bcar bcbc bcca bccc bcda bcra bd-r bdbc bddc brab brac brad brca brcb brda brrr c-cd caaa caab caac caba cac- caca cacc cacr cada cadc cadd cadr cara carb carc card carr cbac cbar cbbc cbca cbcc cbcr cbdb cbdc cbrd ccaa ccab ccac ccad ccar ccba ccbc ccca cccb cccc ccdc ccdr ccra ccrc cd-r cdaa cdac cdad cdba cdda cddb cddr crab crac crar crbc crca crcc crcr crda crdc daab daad daar daba dabb daca dada dara darb darc dard darr dbar dbcc dcbc dcca dccb dccc dcdb dcra dddd ddrc draa drab drac drad drar drba drbc drca drda drra raab raad raba rabb rac- raca racc rada radc radd radr rara rarb rbbb rbbr rcac rcbc rccb rccc rcdc rcrd rdac rrad rrrr