a-a a-b aaa aab aan aao aas aau ab- aba abb abn abo abs abu an- ana anb ann ano ans anu aoa aob aon aoo aos aou as- asa asb asn aso ass asu au- aua aub aun auo aus b-u baa bab ban bao bas bau bba bbb bbn bbo bbs bbu bna bnb bnn bno bns bnu boa bob bon boo bos bou bsa bsb bsn bso bss bsu bua bub bun buo bus buu naa nab nan nao nas nau nba nbb nbn nbo nbs nbu nna nnb nnn nno nns nnu no- noa nob non noo nos nou nsa nsb nsn nso nss nsu nua nub nun nuo nus nuu oaa oab oan oao oas oau ob- oba obb obn obo obs obu on- ona onb onn ono ons onu oo- ooa oob oon ooo oos os- osa osb osn oso oss osu ou- oua oun ouo ous saa sab san sao sas sau sba sbb sbn sbo sbs sbu sna snb snn sno sns snu soa sob son soo sos sou ss- ssa ssb ssn sso sss ssu sua sub sun suo sus suu ua- uaa uab uan uao uas uau uba ubb ubn ubo ubs ubu un- una unb unn uno uns unu uoa uob uon uoo uos usa usb usn uso uss usu uua uun uus uuu