aaaa aaab aaac aaar aaba aabb aabc aaca aacb aacc aaco aacr aacu aaoo aara aarc aaro aaru abaa abab abac abar abau abb- abba abbb abbo abbr abca abcb abcc abcr aboa abob aboo abor abou abra abrc abro abua acaa acab acac acar acba acca accc acco accu acoa acor acou acr- acra acrc acro acrr acu- acuo acur aoba aoca aora aorb arab arac arar arau arba arc- arca arco aroa arob aroo aror arr- arra arrc arro arrr arru arua arub auaa auca aur- aura auro baaa baar baba babb babo babr babu bac- baca bacc baco bar- bara barb barc baro barr baru bau- baur bbau bbbb bbrc bcaa bcar bcbc bcca bccc bcor bcra bcru bcuc boab boac boar boba bobb bobo bobu boca boco bocu boob booc boor bor- bora boro borr boru boua bour brab brac brao brau brca brcb broa brob broc broo bror brou brrr bruc buar buba bubb bubo bubu buca bucc buco bucu bur- bura burb buro burr buru c-bo caaa caab caac caba cabo cabu cac- caca cacc caco cacr caor cara carb carc caro carr cauc cauo cbac cbar cbbc cbca cbcc cbcr cbcu ccaa ccab ccac ccar ccba ccbc ccca cccb cccc cccu ccob ccoc ccra ccrc ccuc coba cobb cobo cobu coca coco cocu coob cor- cora corb corc coro corr coua coub cour crab crac crar crau crbc crbu crca crcc crcr crob croc croo cror crub cuau cub- cuba cubb cuca cucc cura curb curo curr oaau oara obba obbo obor obra obro ocab ocac ocbc occa occc ocra ocro ocrr ocur ooaa ooba oocr oooo oora orab orac orao orar orba orbb orbo orbu orca orco oro- oror orra orro orub ouac oucc our- oura ouro ouu- raab raba rabb rabo rabu rac- raca racc raco racu raob raoc rara rarb raro raua raub rauc rbbb rbbr rcac rcbc rcbo rccb rccc roab roar rob- roba robb robo robu roca rocc roco roob roor rora rorc roro roru roua roub rrrr ruba rubb rubu ruca rura rurc ruro ruru uabc uaca uaoc uarc uaru uaua ubac ubar ubba ubbo uboc ubra ucar ucbc ucca ucrc ucua uocc uor- urac urao urau urba urca uro- uroa uroo urra urur uuoc uuuu