a-a a-b a-i aaa aab aai aak aas aay ab- aba abb abi abk abs aby ai- aia aib aii aik ais aiy aka akb aki akk aks as- asa asb asi ask ass asy ay- aya ayi ayk ays baa bab bai bak bas bay bba bbb bbi bbk bbs bby bi- bia bib bii bik bis biy bka bkb bkk bks bsa bsb bsi bsk bss bsy by- bya byi byk bys ia- iaa iab iai ias iba ibb ibi ibk ibs iby iia iib iii iis ika ikb iki ikk iks is- isa isb isi isk iss isy iya iys iyy ka- kaa kab kai kak kas kay kba kbb kbi kbk kbs kia kib kii kik kis kkb kki kkk kks kky ksa ksb ksi ksk kss kya kys saa sab sai sak sas say sba sbb sbi sbk sbs sby sia sib sii sik sis sk- ska skb ski skk sks sky ss- ssa ssb ssi ssk sss sy- sya syb syi syk sys yaa yab yai yak yas yay ybi ybs yby yii yis yka yki ykk ysa ysb ysi ysk yss ysy yyb yys yyy