-vac a-ak a-ok aaaa aaac aaav aaca aacc aack aaco aacv aaka aaoo aava acaa acac acca accc acco acoa acvv akaa akao akca akka akko akok aoca avao avcc avco avva avvo caaa caac cac- caca cacc cack caco caka cava cavo ccaa ccac ccca cccc cccv ccoc ccvo ckac ckck ckco ckcv ckoa ckoc ckoo ckvo coak coca cock coco cok- coka coko cook cova covo cvac cvca cvcc kaaa kaak kacc kaco kacv kaka kakc kakk kako kaoa kaoc kaok kava kavo kavv kcaa kcac kcav kcca kccc kcck kccv kckc kckk kcko kckv kcvk kcvo kcvv kkaa kkac kkck kkco kkkk kkoa kkoo kkov kkvv koac koak koca kock koka kokc kokk koko kooc kook kooo koov kova kovc kovk kovo kvak kvcc kvck kvco kvcv kvoa kvoc kvok kvoo kvov kvvv ocac ocak occa occc okak okka okko okok ooaa ooak oooo ovo- ovoo vaca vack vaco vaka vava voca voka vooc vovk vvvv