a-a a-c aaa aac aad aao aas ac- aca acc acd aco acs ad- ada adc add ado ads aoa aoc aod aoo aos as- asa asc asd aso ass c-- caa cac cad cao cas cca ccc ccd cco ccs cda cdc cdd cdo cds co- coa coc cod coo cos csa csc csd cso css daa dac dad dao das dca dcc dcd dco dcs dda ddc ddd ddo dds doa doc dod doo dos dsa dsc dsd dso dss oaa oac oad oao oas oc- oca occ ocd oco ocs oda odc odd odo ods oo- ooa ooc ood ooo oos os- osa osc osd oso oss saa sac sad sao sas sca scc scd sco scs sda sdc sdd sdo sds soa soc sod soo sos ss- ssa ssc ssd sso sss