a-a a-b a-c a-t aaa aab aac aae aao aat aau ab- aba abb abc abe abo abt abu ac- aca acb acc ace aco act acu aea aeb aec aee aeo aet aeu aoa aob aoc aoe aoo aot aou at- ata atb atc ate ato att atu au- aua aub auc aue auo aut b-u baa bab bac bae bao bat bau bba bbb bbc bbe bbo bbt bbu bca bcb bcc bce bco bct bcu be- bea beb bec bee beo bet beu boa bob boc boe boo bot bou bta btb btc bte bto btt btu bua bub buc bue buo but buu c-- caa cab cac cae cao cat cau cba cbb cbc cbe cbo cbt cbu cca ccb ccc cce cco cct ccu ce- cea ceb cec cee ceo cet ceu co- coa cob coc coe coo cot cou cta ctb ctc cte cto ctt ctu cua cub cuc cue cuo cut cuu eaa eab eac eae eao eat eau eba ebb ebc ebe ebo ebt ebu ec- eca ecb ecc ece eco ect ecu eea eeb eec eee eeo eet eo- eoa eob eoc eoe eoo eot eou eta etb etc ete eto ett etu eu- eua eub euc eue eut oaa oab oac oae oao oat oau ob- oba obb obc obe obo obt obu oc- oca ocb occ oco oct ocu oea oeb oec oee oeo oet oo- ooa oob ooc ooo oot ot- ota otb otc ote oto ott otu ou- oua ouc oue ouo out taa tab tac tae tao tat tau tba tbb tbc tbe tbo tbt tbu tca tcb tcc tce tco tct tcu te- tea teb tec tee teo tet teu to- toa tob toc toe too tot tou tta ttb ttc tte tto ttt ttu tua tub tuc tue tuo tut tuu ua- uaa uab uac uae uao uat uau uba ubb ubc ube ubo ubt ubu uca ucb ucc uce uco uct ucu uea ueb uec uee uet uoa uob uoc uoe uoo uot uta utb utc ute uto utt utu uua uuc uue uut uuu