okd oke okk okl oko okr oks ola olc old ole olf olk oll olo ols oo- ooa ooc ood oof ooh ook ool ooo oor oos or- ora orc ord ore orf orh ork orl oro orr ors os- osa osc osd ose osf osh osk osl oso osr oss ra- raa rac rad rae raf rah rak ral rao rar ras rca rcc rcd rce rcf rch rcl rco rcr rcs rda rdc rdd rde rdf rdh rdl rdo rdr rds re- rea rec red ree ref reh rek rel reo rer res rfa rfc rfd rfe rff rfh rfk rfl rfo rfr rfs rh- rha rhc rhd rhe rhf rhh rhl rho rhr rhs rkc rke rkf rkk rko rks rla rlc rld rle rlf rlh rll rlo rlr rls roa roc rod roe rof roh rok rol roo ror ros rra rrc rrd rrf rrh rrk rrl rrr rrs rsa rsc rsd rse rsf rsh rsk rsl rso rsr rss saa sac sad sae saf sah sak sal sao sar sas sca scc scd sce scf sch sck scl sco scr scs sda sdc sdd sde sdf sdh sdk sdl sdo sdr sds se- sea sec sed see sef seh sek sel seo ser ses sfa sfc sfd sfe sff sfh sfk sfl sfo sfr sfs sh- sha shc shd she shf shh shk shl sho shr shs sk- ska skc skd ske skf skh skk skl sko skr sks sla slc sld sle slf slh slk sll slo slr sls soa soc sod soe sof soh sok sol soo sor sos sr- sra src srd sre srf srh srk srl sro srr srs ss- ssa ssc ssd sse ssf ssh ssk ssl sso ssr sss