a-a a-b a-i aaa aab aae aai aas aau aax ab- aba abb abe abi abs abu abx aea aeb aee aei aes aeu aex ai- aia aib aie aii ais aiu aix as- asa asb ase asi ass asu asx au- aua aub aue aui aus aux ax- axa axe axi axs axx b-u baa bab bae bai bas bau bax bba bbb bbe bbi bbs bbu bbx be- bea beb bee bei bes beu bex bi- bia bib bie bii bis biu bix bsa bsb bse bsi bss bsu bsx bua bub bue bui bus buu bux bxb bxi bxx eaa eab eae eai eas eau eax eba ebb ebe ebi ebs ebu ebx eea eeb eee ees eex eia eib eie eii eis eiu eix es- esa esb ese esi ess esu esx eu- eua eub eue eui eus eux ex- exa exe exi exs exu exx ia- iaa iab iae iai ias iau iba ibb ibe ibi ibs ibu ibx ie- iea iee iei ies iex iia iib iie iii iis iiu iix is- isa isb ise isi iss isu iu- iua iub iue iui ius ixe ixi saa sab sae sai sas sau sax sba sbb sbe sbi sbs sbu sbx se- sea seb see sei ses seu sex sia sib sie sii sis siu six ss- ssa ssb sse ssi sss ssu ssx sua sub sue sui sus suu sux sxi sxs sxu ua- uaa uab uae uai uas uau uba ubb ube ubi ubs ubu ubx uea ueb uee uei ues uia uib uie uii uis uiu usa usb use usi uss usu usx uua uue uus uuu uxb uxu xaa xas xau xbe xbx xee xes xeu xex xia xie xii xis xiu xix xsa xsb xsi xss xue xui xus xxi xxx