a-a a-b a-c aaa aab aac aak aam aay ab- aba abb abc abk abm aby ac- aca acb acc ack acm acy aka akb akc akk akm ama amb amc amk amm amy ay- aya ayc ayk baa bab bac bak bam bay bba bbb bbc bbk bbm bby bca bcb bcc bck bcm bcy bka bkb bkc bkk bkm bma bmb bmc bmk bmm by- bya byc byk bym c-- caa cab cac cak cam cay cba cbb cbc cbk cbm cby cca ccb ccc cck ccm cka ckb ckc ckm cky cma cmb cmc cmk cmm cmy cya cyb cyc cyk cym ka- kaa kab kac kak kam kay kba kbb kbc kbk kbm kca kcb kcc kck kcm kkb kkc kkk kkm kky kma kmb kmc kmk kmm kya kyc kym maa mab mac mak mam may mba mbb mbc mbk mbm mc- mca mcb mcc mck mcm mka mkb mkc mkk mkm mky mma mmb mmc mmk mmm my- mya myb myc myk mym yaa yab yac yak yam yay ybc ybm yby yca ycc ycy yka ykk ykm yma ymc ymm yyb yyc yyy