a-a a-b a-t aaa aab aak aao aat aau ab- aba abb abk abo abt abu aka akb akk ako aku aoa aob aok aoo aot aou at- ata atb ato att atu au- aua aub auk auo aut b-u baa bab bak bao bat bau bba bbb bbk bbo bbt bbu bka bkb bkk bko bkt boa bob bok boo bot bou bta btb btk bto btt btu bua bub buk buo but buu k-t ka- kaa kab kak kao kat kau kba kbb kbk kbo kbu kkb kkk kkt kku koa kob kok koo kot kou kta ktb ktk kto ktt ktu kub kuk kut kuu oaa oab oak oao oat oau ob- oba obb obk obo obt obu oka okb okk oko oku oo- ooa oob ook ooo oot ot- ota otb otk oto ott otu ou- oua ouk ouo out taa tab tak tao tat tau tba tbb tbk tbo tbt tbu tka tkb tkk tko tkt to- toa tob tok too tot tou tta ttb ttk tto ttt ttu tua tub tuk tuo tut tuu ua- uaa uab uak uao uat uau uba ubb ubk ubo ubt ubu uka ukb ukk uku uoa uob uok uoo uot uta utb utk uto utt utu uua uut uuu