a-a a-b aaa aab aah aan aao aar aau ab- aba abb abh abn abo abr abu aha ahb ahh ahn aho ahr ahu an- ana anb anh ann ano anr anu aoa aob aoh aon aoo aor aou ar- ara arb arh arn aro arr aru au- aua aub auh aun auo aur b-u baa bab bah ban bao bar bau bba bbb bbh bbn bbo bbr bbu bha bhb bhh bho bhr bhu bna bnb bnn bno bnr bnu boa bob boh bon boo bor bou bra brb brh brn bro brr bru bua bub buh bun buo bur buu haa hab hah han hao har hau hba hbb hbh hbn hbo hbr hbu hha hhb hhh hhn hho hhr hhu hna hnb hnh hnn hno hnu hoa hob hoh hon hoo hor hou hr- hra hrb hrh hrn hro hrr hru hua hub huh hun huo hur huu naa nab nah nan nao nar nau nba nbb nbn nbo nbr nbu nha nhb nhh nhn nhr nhu nna nnb nnh nnn nno nnu no- noa nob noh non noo nor nou nra nrb nrn nro nrr nru nua nub nuh nun nuo nur nuu oaa oab oah oan oao oar oau ob- oba obb obh obn obo obr obu oha ohh ohn oho ohr ohu on- ona onb onh onn ono onr onu oo- ooa oob ooh oon ooo oor or- ora orb orh orn oro orr oru ou- oua ouh oun ouo our ra- raa rab rah ran rao rar rau rba rbb rbh rbn rbo rbr rbu rh- rha rhb rhh rhn rho rhr rhu rna rnb rnh rnn rno rnr rnu roa rob roh ron roo ror rou rra rrb rrh rrn rrr rru rua rub ruh run ruo rur ruu ua- uaa uab uah uan uao uar uau uba ubb ubh ubn ubo ubr ubu uha uhb uhh uho uhr uhu un- una unb unh unn uno unr unu uoa uob uon uoo uor ur- ura urb urn uro urr uru uua uun uur uuu