a-a a-b a-t aaa aab aak aao aat aay ab- aba abb abk abo abt aby aka akb akk ako aoa aob aok aoo aot at- ata atb ato att ay- aya ayk ayo ayt baa bab bak bao bat bay bba bbb bbk bbo bbt bby bka bkb bkk bko bkt boa bob bok boo bot boy bta btb btk bto btt bty by- bya byk byo byt k-t ka- kaa kab kak kao kat kay kba kbb kbk kbo kkb kkk kkt kky koa kob kok koo kot koy kta ktb ktk kto ktt kya kyo kyt oaa oab oak oao oat ob- oba obb obk obo obt oby oka okb okk oko oo- ooa oob ook ooo oot ot- ota otb otk oto ott oya oyo taa tab tak tao tat tay tba tbb tbk tbo tbt tka tkb tkk tko tkt tky to- toa tob tok too tot toy tta ttb ttk tto ttt tty tya tyo tyt yaa yab yak yao yat yay yby yka ykk yob yok yoo yot yoy yta ytk yto ytt yyb yyt yyy