a-a a-b aaa aab aak aar aas aay ab- aba abb abk abr abs aby aka akb akk akr aks ar- ara arb ark arr ars ary as- asa asb ask asr ass asy ay- aya ayk ayr ays baa bab bak bar bas bay bba bbb bbk bbr bbs bby bka bkb bkk bkr bks bra brb brk brr brs bry bsa bsb bsk bsr bss bsy by- bya byk byr bys ka- kaa kab kak kar kas kay kba kbb kbk kbr kbs kkb kkk kkr kks kky kra krk krr krs kry ksa ksb ksk ksr kss kya kyr kys ra- raa rab rak rar ras ray rba rbb rbk rbr rbs rkb rkk rks rky rra rrb rrk rrr rrs rsa rsb rsk rsr rss ry- rya ryk ryr rys ryy saa sab sak sar sas say sba sbb sbk sbr sbs sby sk- ska skb skk skr sks sky sr- sra srb srk srr srs sry ss- ssa ssb ssk ssr sss sy- sya syb syk syr sys yaa yab yak yar yas yay ybr ybs yby yka ykk yra yrs ysa ysb ysk ysr yss ysy yyb yys yyy