-vac aaaa aaab aaac aaav aaba aabb aabc aabt aaca aacb aacc aaco aact aacv aaoo aata aatc aatt aava abaa abab abac abat abb- abba abbb abbo abbt abca abcb abcc abct aboa abob aboo abot abov abta abva ac-t acaa acab acac acat acba acca accc acco acct acoa acot acta actc acto actt actv acvv aoba aoca aotc at-t ataa atab atac atat atca atcc atco atob atoc atot atta atto avab avao avat avcc avco avot avva avvo baaa baat baba babb babo bac- baca bacc baco bact bata batc bato batt bava bbbb bcaa bcat bcbc bcca bccc bctc bcvo boab boac boat boba bobb bobo boca boco boob booc boot bota botb boto bott bova bovo btaa btcc btob bttb c-bo caaa caab caac caat caba cabo cac- caca cacc caco cat- cata catb catc cato catt catv cava cavo cbac cbat cbbc cbca cbcc cbct cbot cbta cbtc cbtv cbva cbvb ccaa ccab ccac ccat ccba ccbc ccca cccb cccc cccv ccob ccoc cctb cctc cctt cctv ccvo coat coba cobb cobo coca coco coct coob coot cota cotb cotc coto cott cova covo ctab ctba ctca ctot ctta ctvo ctvt cvac cvca cvcc obba obbo obot ocab ocac ocat ocbc occa occc occt oct- octa octo ooaa ooba oooo ootb otac oto- otoo otov otta otto ovo- ovoo ovot taa- taat taba tabb tabc tabo taca tacc taco tact tacv taoa tata tatb tato tatt tatv tava tavo tbca tbcb tbcc tbta tcca tccc tcov tctc toab toat toba tobo tobt toca toco tooa toot tota totc toto tott tova tovo ttab ttbb tttt tvac tvtv vaat vaca vaco vata vato vatt vava vbcc vcat voat voca vooc voot vota voto vtac vvob vvvv