a-a a-c aaa aac aae aao aas ac- aca acc ace aco acs aea aec aee aeo aes aoa aoc aoe aoo aos as- asa asc ase aso ass c-- caa cac cae cao cas cca ccc cce cco ccs ce- cea cec cee ceo ces co- coa coc coe coo cos csa csc cse cso css eaa eac eae eao eas ec- eca ecc ece eco ecs eea eec eee eeo ees eo- eoa eoc eoe eoo eos es- esa esc ese eso ess oaa oac oae oao oas oc- oca occ oco ocs oea oec oee oeo oes oo- ooa ooc ooo oos os- osa osc ose oso oss saa sac sae sao sas sca scc sce sco scs se- sea sec see seo ses soa soc soe soo sos ss- ssa ssc sse sso sss