a-a a-b a-i aaa aab aai aam aax aay ab- aba abb abi abm abx aby ai- aia aib aii aim aix aiy ama amb ami amm amx amy ax- axa axi axm axx ay- aya ayi ayx baa bab bai bam bax bay bba bbb bbi bbm bbx bby bi- bia bib bii bim bix biy bma bmb bmi bmm bmx bxb bxi bxm bxx by- bya byi bym ia- iaa iab iai iam iba ibb ibi ibm ibx iby iia iib iii iim iix im- ima imb imi imm imx imy ixi ixy iya iym iyy maa mab mai mam max may mba mbb mbi mbm mbx mi- mia mib mii mim mix miy mma mmb mmi mmm mmx mxa mxi my- mya myb mym myx xaa xam xbx xia xii xix xma xmi xmm xmx xxi xxx xxy xyy yaa yab yai yam yax yay ybi ybm yby yii yim yma ymi ymm yxa yxy yyb yyy