ddd ddf ddo ddr dds dfd dff dfo dfr dfs dod dof doo dor dos drd dro drr drs dsd dsf dso dsr dss fdd fdf fdo fdr fds ffd fff ffo ffr ffs fof foo for fos frd frf fro frr frs fsd fsf fso fsr fss odd odf odo odr ods of- ofd off ofo ofr ofs oo- ood oof ooo oor oos or- ord orf oro orr ors os- osd osf oso osr oss rdd rdf rdo rdr rds rfd rff rfo rfr rfs rod rof roo ror ros rrd rrf rrr rrs rsd rsf rso rsr rss sdd sdf sdo sdr sds sfd sff sfo sfr sfs sod sof soo sor sos sr- srd srf sro srr srs ss- ssd ssf sso ssr sss