a-a a-b a-c a-t aaa aab aac aao aat aau ab- aba abb abc abo abt abu ac- aca acb acc aco act acu aoa aob aoc aoo aot aou at- ata atb atc ato att atu au- aua aub auc auo aut b-u baa bab bac bao bat bau bba bbb bbc bbo bbt bbu bca bcb bcc bco bct bcu boa bob boc boo bot bou bta btb btc bto btt btu bua bub buc buo but buu c-- caa cab cac cao cat cau cba cbb cbc cbo cbt cbu cca ccb ccc cco cct ccu co- coa cob coc coo cot cou cta ctb ctc cto ctt ctu cua cub cuc cuo cut cuu oaa oab oac oao oat oau ob- oba obb obc obo obt obu oc- oca ocb occ oco oct ocu oo- ooa oob ooc ooo oot ot- ota otb otc oto ott otu ou- oua ouc ouo out taa tab tac tao tat tau tba tbb tbc tbo tbt tbu tca tcb tcc tco tct tcu to- toa tob toc too tot tou tta ttb ttc tto ttt ttu tua tub tuc tuo tut tuu ua- uaa uab uac uao uat uau uba ubb ubc ubo ubt ubu uca ucb ucc uco uct ucu uoa uob uoc uoo uot uta utb utc uto utt utu uua uuc uut uuu