a-ak a-ok aaaa aaab aaac aaba aabb aabc aaca aacb aacc aack aaco aaka aaoo abaa abab abac abag abak abb- abba abbb abbo abca abcb abcc aboa abob abok aboo acaa acab acac acag acba acca accc acco acga acoa acog ag-o agac agag agao agba agbo agca agcc agco agga agob agog agoo akaa akao akca akka akko akok aoba aoca baaa baak baba babb babo bac- baca bacc back baco baga bagg bago bak- baka bako bbbb bbga bcaa bcbc bcbg bcca bccc bgca boab boac boag boak boba bobb bobo boca bock boco boga bogg bogo boka boko boob booc boog book c-bo caaa caab caac caba cabg cabo cac- caca cacc cack caco caga cagg cago caka cbac cbbc cbca cbcc cbga cbgb cbka cbkg cbko ccaa ccab ccac ccag ccba ccbc ccca cccb cccc ccga ccgc ccob ccoc cgac cgcc cgcg ckac ckbc ckck ckco ckga ckgo ckoa ckob ckoc ckoo coag coak coba cobb cobo coca cock coco cogo cok- coka coko coob cook gaba gabb gabo gack gaga gagg gago gbag gbbo gc-c gcaa gcbc gccc gcoa gggg goba gobo goca goga gogo goog gook kaaa kaab kaag kaak kaba kabb kabc kabg kabo kacb kacc kaco kag- kaga kagb kagc kagg kago kaka kakc kakk kako kaoa kaoc kaog kaok kbaa kbab kbac kbak kbba kbbb kbbc kbbg kbbk kbbo kbca kbcb kbck kbco kbga kbgb kbgg kbgo kbkb kbkg kbkk kbko kboa kbob kboc kbok kboo kcaa kcab kcac kcba kcbc kcbk kcca kccb kccc kcck kcgc kckc kckk kcko kcob kcog kgab kgac kgak kgba kgbb kgbc kgcb kgcc kgga kggg kggo kkaa kkac kkag kkba kkbb kkbg kkbo kkcb kkck kkco kkgb kkgo kkkk kkoa kkob kkoo koab koac koak koba kobb kobc kobk kobo koca kocb kock koga kogb kogg kogo koka kokb kokc kokk koko koob kooc koog kook kooo obak obba obbo obkb obok ocab ocac ocak ocbc occa occc ocga ogb ogba ogoa ogog okak okgo okka okko okok ooaa ooak ooba oooo