a-a a-c aaa aac aao aas aay ac- aca acc aco acs acy aoa aoc aoo aos as- asa asc aso ass asy ay- aya ayc ayo ays c-- caa cac cao cas cay cca ccc cco ccs co- coa coc coo cos coy csa csc cso css csy cya cyc cyo cys oaa oac oao oas oc- oca occ oco ocs oo- ooa ooc ooo oos os- osa osc oso oss oya oyo oys saa sac sao sas say sca scc sco scs soa soc soo sos soy ss- ssa ssc sso sss sy- sya syc sys yaa yac yao yas yay yca ycc yco ycs ycy yoc yoo yos yoy ysa ysc yso yss ysy yyc yys yyy