a-a a-b a-c aaa aab aac aah aar aay ab- aba abb abc abh abr aby ac- aca acb acc ach acr acy aha ahb ahc ahh ahr ahy ar- ara arb arc arh arr ary ay- aya ayc ayh ayr baa bab bac bah bar bay bba bbb bbc bbh bbr bby bca bcb bcc bch bcr bcy bha bhb bhc bhh bhr bra brb brh brr bry by- bya byc byh byr c-- caa cab cac cah car cay cba cbb cbc cbh cbr cby cca ccb ccc cch ccr ch- cha chb chc chh chr chy cra crb crc crh crr cry cya cyb cyc cyr haa hab hac hah har hay hba hbb hbc hbh hbr hby hca hcb hcc hch hcr hcy hha hhb hhc hhh hhr hhy hr- hra hrb hrc hrh hrr hy- hya hyb hyc hyh hyr hyy ra- raa rab rac rah rar ray rba rbb rbc rbh rbr rca rcb rcc rch rcr rh- rha rhb rhc rhh rhr rra rrb rrc rrh rrr ry- rya ryc ryr ryy yaa yab yac yah yar yay ybc ybr yby yca ycc ych ycy yha yhc yra yrc yyb yyc yyy