a-a a-z aaa aao aap aar aas aaz aoa aoo aop aor aos ap- apa apo app apr aps ar- ara aro arp arr ars arz as- asa aso asp asr ass asz az- aza azo azp azs azz oaa oao oap oar oas oo- ooa ooo oop oor oos op- opa opo opp opr ops or- ora oro orp orr ors orz os- osa oso osp osr oss oza ozo ozs ozz p-p paa pao pap par pas paz poa poo pop por pos poz ppa ppo ppp ppr pps ppz pra pro prp prr prs prz ps- psa pso psp psr pss pzp ra- raa rao rap rar ras raz roa roo rop ror ros roz rpa rpo rpp rpr rps rpz rra rrp rrr rrs rsa rso rsp rsr rss rza rzo saa sao sap sar sas saz soa soo sop sor sos soz spa spo spp spr sps spz sr- sra sro srp srr srs ss- ssa sso ssp ssr sss ssz sza szp szr zaa zao zap zar zas zaz zo- zoa zoo zor zos zpo zpp zpr zro zrp zrs zsa zsz zzr zzs zzz