aaaa aaab aaac aaba aabb aabc aabt aaca aacb aacc aaco aact aacu aaoo aata aatc aatt abaa abab abac abat abau abb- abba abbb abbo abbt abca abcb abcc abct aboa abob aboo abot abou abta abtu abua abut ac-t acaa acab acac acat acba acca accc acco acct accu acoa acot acou acta actc acto actt actu acu- acuo acut aoba aoca aotc aout at-t ataa atab atac atat atca atcc atco atob atoc atot atta atto attu atua atub atuc auaa auca auct aut- auto baaa baat baba babb babo babu bac- baca bacc baco bact bata batc bato batt batu bau- bbau bbbb bcaa bcat bcbc bcca bccc bctc bcuc boab boac boat boba bobb bobo bobu boca boco bocu boob booc boot bota botb boto bott boua bout btaa btcc btob bttb buat buba bubb bubo bubu buca bucc buco bucu but- buta buto butt c-bo caaa caab caac caat caba cabo cabu cac- caca cacc caco cat- cata catb catc cato catt catu cauc cauo caut cbac cbat cbbc cbca cbcc cbct cbcu cbot cbta cbtc ccaa ccab ccac ccat ccba ccbc ccca cccb cccc cccu ccob ccoc cctb cctc cctt ccuc ccut coat coba cobb cobo cobu coca coco coct cocu coob coot cota cotb cotc coto cott cotu coua coub cout ctab ctba ctca ctot ctta cuau cub- cuba cubb cuca cucc cut- cuta cutc cuto cutt oaau obba obbo obot ocab ocac ocat ocbc occa occc occt oct- octa octo ooaa ooba oooo ootb otac oto- otoo otta otto ottu ouac ouat oucc out- outa outb outo ouu- taa- taat taba tabb tabc tabo tabu taca tacc taco tact taoa taou tata tatb tato tatt tatu taua taub tauc taut tbca tbcb tbcc tbta tcca tccc tccu tctc toab toat toau toba tobo tobt tobu toca toco tooa toot tota totc toto tott tout ttab ttbb tttt tuao tuat tuba tubb tubo tubu tuca tucc tuco tuta tuto tutt tutu tuuo uabc uaca uaoc uata uatu uaua ubac ubba ubbo uboc ucat ucbc ucca ucua ucut uocc utac utau utto uttu uuoc uuta uuuu