aaaa aaab aaac aaba aabb aabc aabt aaca aacb aacc aaco aact aaoo aata aatc aatt abaa abab abac abat abb- abba abbb abbo abbt abca abcb abcc abct aboa abob aboo abot abta ac-t acaa acab acac acat acba acca accc acco acct acoa acot acta actc acto actt aoba aoca aotc at-t ataa atab atac atat atca atcc atco atob atoc atot atta atto baaa baat baba babb babo bac- baca bacc baco bact bata batc bato batt bbbb bcaa bcat bcbc bcca bccc bctc boab boac boat boba bobb bobo boca boco boob booc boot bota botb boto bott btaa btcc btob bttb c-bo caaa caab caac caat caba cabo cac- caca cacc caco cat- cata catb catc cato catt cbac cbat cbbc cbca cbcc cbct cbot cbta cbtc ccaa ccab ccac ccat ccba ccbc ccca cccb cccc ccob ccoc cctb cctc cctt coat coba cobb cobo coca coco coct coob coot cota cotb cotc coto cott ctab ctba ctca ctot ctta obba obbo obot ocab ocac ocat ocbc occa occc occt oct- octa octo ooaa ooba oooo ootb otac oto- otoo otta otto taa- taat taba tabb tabc tabo taca tacc taco tact taoa tata tatb tato tatt tbca tbcb tbcc tbta tcca tccc tctc toab toat toba tobo tobt toca toco tooa toot tota totc toto tott ttab ttbb tttt