a-a a-b a-c aaa aab aac aah aay ab- aba abb abc abh aby ac- aca acb acc ach acy aha ahb ahc ahh ahy ay- aya ayc ayh baa bab bac bah bay bba bbb bbc bbh bby bca bcb bcc bch bcy bha bhb bhc bhh by- bya byc byh c-- caa cab cac cah cay cba cbb cbc cbh cby cca ccb ccc cch ch- cha chb chc chh chy cya cyb cyc haa hab hac hah hay hba hbb hbc hbh hby hca hcb hcc hch hcy hha hhb hhc hhh hhy hy- hya hyb hyc hyh hyy yaa yab yac yah yay ybc yby yca ycc ych ycy yha yhc yyb yyc yyy