ddd ddf ddo ddp ddr dds dfd dff dfo dfp dfr dfs dod dof doo dop dor dos dpd dpf dpo dpp dpr dps drd dro drp drr drs dsd dsf dso dsp dsr dss fdd fdf fdo fdp fdr fds ffd fff ffo ffp ffr ffs fof foo fop for fos fpd fpo fpp fpr fps frd frf fro frp frr frs fsd fsf fso fsp fsr fss odd odf odo odp odr ods of- ofd off ofo ofp ofr ofs oo- ood oof ooo oop oor oos op- opd opf opo opp opr ops or- ord orf oro orp orr ors os- osd osf oso osp osr oss p-p pdd pdf pdo pdp pdr pds pfd pff pfo pfp pfr pfs pod pof poo pop por pos ppd ppf ppo ppp ppr pps prd prf pro prp prr prs ps- psd psf pso psp psr pss rdd rdf rdo rdp rdr rds rfd rff rfo rfp rfr rfs rod rof roo rop ror ros rpd rpf rpo rpp rpr rps rrd rrf rrp rrr rrs rsd rsf rso rsp rsr rss sdd sdf sdo sdp sdr sds sfd sff sfo sfp sfr sfs sod sof soo sop sor sos spd spf spo spp spr sps sr- srd srf sro srp srr srs ss- ssd ssf sso ssp ssr sss