a-a aaa aaf aao aap aar aas af- afa aff afo afp afr afs aoa aof aoo aop aor aos ap- apa apf apo app apr aps ar- ara arf aro arp arr ars as- asa asf aso asp asr ass faa faf fao fap far fas ffa fff ffo ffp ffr ffs foa fof foo fop for fos fpa fpo fpp fpr fps fra frf fro frp frr frs fsa fsf fso fsp fsr fss oaa oaf oao oap oar oas of- ofa off ofo ofp ofr ofs oo- ooa oof ooo oop oor oos op- opa opf opo opp opr ops or- ora orf oro orp orr ors os- osa osf oso osp osr oss p-p paa paf pao pap par pas pfa pff pfo pfp pfr pfs poa pof poo pop por pos ppa ppf ppo ppp ppr pps pra prf pro prp prr prs ps- psa psf pso psp psr pss ra- raa raf rao rap rar ras rfa rff rfo rfp rfr rfs roa rof roo rop ror ros rpa rpf rpo rpp rpr rps rra rrf rrp rrr rrs rsa rsf rso rsp rsr rss saa saf sao sap sar sas sfa sff sfo sfp sfr sfs soa sof soo sop sor sos spa spf spo spp spr sps sr- sra srf sro srp srr srs ss- ssa ssf sso ssp ssr sss