a-a a-c aaa aac aah aao aas ac- aca acc ach aco acs aha ahc ahh aho ahs aoa aoc aoh aoo aos as- asa asc ash aso ass c-- caa cac cah cao cas cca ccc cch cco ccs ch- cha chc chh cho chs co- coa coc coh coo cos csa csc csh cso css haa hac hah hao has hca hcc hch hco hcs hha hhc hhh hho hhs hoa hoc hoh hoo hos hsa hsc hsh hss oaa oac oah oao oas oc- oca occ och oco ocs oha ohc ohh oho ohs oo- ooa ooc ooh ooo oos os- osa osc osh oso oss saa sac sah sao sas sca scc sch sco scs sh- sha shc shh sho shs soa soc soh soo sos ss- ssa ssc ssh sso sss