ddd ddm ddo dds ddt dmd dmm dmo dms dmt dod dom doo dos dot dsd dsm dso dss dst dtd dtm dto dts dtt m-o mdd mdm mdo mds mdt mmd mmm mmo mms mmt mod mom moo mos mot msd msm mso mss mst mtd mtm mto mts mtt odd odm odo ods odt om- omd omm omo oms omt oo- ood oom ooo oos oot os- osd osm oso oss ost ot- otd otm oto ots ott sdd sdm sdo sds sdt smd smm smo sms smt sod som soo sos sot ss- ssd ssm sso sss sst std stm sto sts stt tdd tdm tdo tds tdt tmd tmm tmo tms tmt to- tod tom too tos tot tsd tsm tso tss tst ttd ttm tto tts ttt