a-a a-b a-c aaa aab aac aah aas ab- aba abb abc abh abs ac- aca acb acc ach acs aha ahb ahc ahh ahs as- asa asb asc ash ass baa bab bac bah bas bba bbb bbc bbh bbs bca bcb bcc bch bcs bha bhb bhc bhh bhs bsa bsb bsc bsh bss c-- caa cab cac cah cas cba cbb cbc cbh cbs cca ccb ccc cch ccs ch- cha chb chc chh chs csa csb csc csh css haa hab hac hah has hba hbb hbc hbh hbs hca hcb hcc hch hcs hha hhb hhc hhh hhs hsa hsb hsc hsh hss saa sab sac sah sas sba sbb sbc sbh sbs sca scb scc sch scs sh- sha shb shc shh shs ss- ssa ssb ssc ssh sss