a-a aaa aaf aao aar aas aav af- afa aff afo afr afs afv aoa aof aoo aor aos aov ar- ara arf aro arr ars arv as- asa asf aso asr ass asv av- ava avf avo avr avs faa faf fao far fas fav ffa fff ffo ffr ffs ffv foa fof foo for fos fra frf fro frr frs fsa fsf fso fsr fss fsv fva oaa oaf oao oar oas oav of- ofa off ofo ofr ofs ofv oo- ooa oof ooo oor oos oov or- ora orf oro orr ors orv os- osa osf oso osr oss osv ov- ova ovf ovo ovs ovv ra- raa raf rao rar ras rav rfa rff rfo rfr rfs rfv roa rof roo ror ros rov rra rrf rrr rrs rsa rsf rso rsr rss rsv rva rvf rvo rvr rvs rvv saa saf sao sar sas sav sfa sff sfo sfr sfs sfv soa sof soo sor sos sov sr- sra srf sro srr srs srv ss- ssa ssf sso ssr sss ssv sva svf svo svr svs svv v-a vaa vao var vas vav vfa vff vfr vfs vfv voa vof voo vor vos vov vra vrf vrr vrs vsa vsf vso vsr vss vsv vva vvo vvr vvs vvv