ddd ddf ddm ddo ddr dds dfd dff dfm dfo dfr dfs dmd dmf dmm dmo dmr dms dod dof dom doo dor dos drd drm dro drr drs dsd dsf dsm dso dsr dss fdd fdf fdm fdo fdr fds ffd fff ffm ffo ffr ffs fmd fmf fmm fmo fmr fms fof fom foo for fos frd frf frm fro frr frs fsd fsf fsm fso fsr fss m-f m-o m-r mdd mdf mdm mdo mdr mds mfd mff mfm mfo mfr mfs mmd mmf mmm mmo mmr mms mod mof mom moo mor mos mrd mrf mrm mro mrr mrs msd msf msm mso msr mss odd odf odm odo odr ods of- ofd off ofm ofo ofr ofs om- omd omf omm omo omr oms oo- ood oof oom ooo oor oos or- ord orf orm oro orr ors os- osd osf osm oso osr oss rdd rdf rdm rdo rdr rds rfd rff rfm rfo rfr rfs rmd rmf rmm rmo rmr rms rod rof rom roo ror ros rrd rrf rrm rrr rrs rsd rsf rsm rso rsr rss sdd sdf sdm sdo sdr sds sfd sff sfm sfo sfr sfs smd smf smm smo smr sms sod sof som soo sor sos sr- srd srf srm sro srr srs ss- ssd ssf ssm sso ssr sss