a-a a-b aaa aab aah aan aao aau ab- aba abb abh abn abo abu aha ahb ahh ahn aho ahu an- ana anb anh ann ano anu aoa aob aoh aon aoo aou au- aua aub auh aun auo b-u baa bab bah ban bao bau bba bbb bbh bbn bbo bbu bha bhb bhh bho bhu bna bnb bnn bno bnu boa bob boh bon boo bou bua bub buh bun buo buu haa hab hah han hao hau hba hbb hbh hbn hbo hbu hha hhb hhh hhn hho hhu hna hnb hnh hnn hno hnu hoa hob hoh hon hoo hou hua hub huh hun huo huu naa nab nah nan nao nau nba nbb nbn nbo nbu nha nhb nhh nhn nhu nna nnb nnh nnn nno nnu no- noa nob noh non noo nou nua nub nuh nun nuo nuu oaa oab oah oan oao oau ob- oba obb obh obn obo obu oha ohh ohn oho ohu on- ona onb onh onn ono onu oo- ooa oob ooh oon ooo ou- oua ouh oun ouo ua- uaa uab uah uan uao uau uba ubb ubh ubn ubo ubu uha uhb uhh uho uhu un- una unb unh unn uno unu uoa uob uon uoo uua uun uuu