aaaa aaab aaac aaar aaba aabb aabc aaca aacb aacc aaco aacr aaoo aara aarc aaro abaa abab abac abar abax abb- abba abbb abbo abbr abca abcb abcc abcr aboa abob aboo abor abox abra abrc abro acaa acab acac acar acba acca accc acco acoa acor acr- acra acrc acro acrr aoba aoca aora aorb arab arac arar arax arba arc- arca arco aroa arob aroo aror arr- arra arrc arro arrr axar axo- axoa axxo ba-x baaa baar baba babb babo babr bac- baca bacc baco bar- bara barb barc baro barr barx bbbb bbox bbrc bcaa bcar bcbc bcca bccc bcor bcra boab boac boar boba bobb bobo boca boco boob booc boor boox bor- bora boro borr boxa brab brac brao brax brca brcb broa brob broc broo bror brox brrr c-bo caaa caab caac caba cabo cac- caca cacc caco cacr caor cara carb carc caro carr carx caxa cbac cbar cbax cbbc cbca cbcc cbcr cbox cbxa ccaa ccab ccac ccar ccba ccbc ccca cccb cccc ccob ccoc ccra ccrc coax coba cobb cobo coca coco coob cor- cora corb corc coro corr coxa crab crac crar crax crbc crca crcc crcr crob croc croo cror cxro cxxx oara obba obbo obor obox obra obro ocab ocac ocbc occa occc ocra ocro ocrr ooaa ooba oocr oooo oora orab orac orao orar orba orbb orbo orca orco oro- oror orra orro oxa- oxo- oxox oxxo raab raba rabb rabo rac- raca racc raco raob raoc rara rarb raro raxa rbbb rbbr rcac rcbc rcbo rccb rccc roab roar rob- roba robb robo roca rocc roco roob roor roox rora rorc roro roxa roxo rrrr xaar xara xbar xbox xbra xobc xoca xoco xoro xoxo xxxo xxxx