a-a a-b aaa aab aam aas aay ab- aba abb abm abs aby ama amb amm ams amy as- asa asb asm ass asy ay- aya ays baa bab bam bas bay bba bbb bbm bbs bby bma bmb bmm bms bsa bsb bsm bss bsy by- bya bym bys maa mab mam mas may mba mbb mbm mbs mma mmb mmm mms msa msb msm mss msy my- mya myb mym mys saa sab sam sas say sba sbb sbm sbs sby sma smb smm sms smy ss- ssa ssb ssm sss sy- sya syb sym sys yaa yab yam yas yay ybm ybs yby yma ymm yms ysa ysb ysm yss ysy yyb yys yyy