a-a aaa aao aap aar aas aoa aoo aop aor aos ap- apa apo app apr aps ar- ara aro arp arr ars as- asa aso asp asr ass oaa oao oap oar oas oo- ooa ooo oop oor oos op- opa opo opp opr ops or- ora oro orp orr ors os- osa oso osp osr oss p-p paa pao pap par pas poa poo pop por pos ppa ppo ppp ppr pps pra pro prp prr prs ps- psa pso psp psr pss ra- raa rao rap rar ras roa roo rop ror ros rpa rpo rpp rpr rps rra rrp rrr rrs rsa rso rsp rsr rss saa sao sap sar sas soa soo sop sor sos spa spo spp spr sps sr- sra sro srp srr srs ss- ssa sso ssp ssr sss