a-a a-b aaa aab aad aan aas aau ab- aba abb abd abn abs abu ad- ada adb add adn ads adu an- ana anb and ann ans anu as- asa asb asd asn ass asu au- aua aub aud aun aus b-u baa bab bad ban bas bau bba bbb bbd bbn bbs bbu bda bdb bdd bds bdu bna bnb bnd bnn bns bnu bsa bsb bsd bsn bss bsu bua bub bud bun bus buu daa dab dad dan das dau dba dbb dbd dbn dbs dbu dda ddb ddd ddn dds ddu dna dnb dnd dnn dns dsa dsb dsd dsn dss dsu dua dub dud dun dus naa nab nad nan nas nau nba nbb nbd nbn nbs nbu nda ndb ndd ndn nds ndu nna nnb nnn nns nnu nsa nsb nsd nsn nss nsu nua nub nud nun nus nuu saa sab sad san sas sau sba sbb sbd sbn sbs sbu sda sdb sdd sdn sds sdu sna snb snd snn sns snu ss- ssa ssb ssd ssn sss ssu sua sub sud sun sus suu ua- uaa uab uad uan uas uau uba ubb ubn ubs ubu uda udb udd udn uds udu un- una unb und unn uns unu usa usb usd usn uss usu uua uun uus uuu