a-a a-b aaa aab aan aas aau ab- aba abb abn abs abu an- ana anb ann ans anu as- asa asb asn ass asu au- aua aub aun aus b-u baa bab ban bas bau bba bbb bbn bbs bbu bna bnb bnn bns bnu bsa bsb bsn bss bsu bua bub bun bus buu naa nab nan nas nau nba nbb nbn nbs nbu nna nnb nnn nns nnu nsa nsb nsn nss nsu nua nub nun nus nuu saa sab san sas sau sba sbb sbn sbs sbu sna snb snn sns snu ss- ssa ssb ssn sss ssu sua sub sun sus suu ua- uaa uab uan uas uau uba ubb ubn ubs ubu un- una unb unn uns unu usa usb usn uss usu uua uun uus uuu