ddd ddo ddr dds ddt dod doo dor dos dot drd dro drr drs drt dsd dso dsr dss dst dtd dto dtr dts dtt odd odo odr ods odt oo- ood ooo oor oos oot or- ord oro orr ors ort os- osd oso osr oss ost ot- otd oto otr ots ott rdd rdo rdr rds rdt rod roo ror ros rot rrd rrr rrs rrt rsd rso rsr rss rst rtd rto rtr rts rtt sdd sdo sdr sds sdt sod soo sor sos sot sr- srd sro srr srs srt ss- ssd sso ssr sss sst std sto str sts stt tdd tdo tdr tds tdt to- tod too tor tos tot trd tro trr trs trt tsd tso tsr tss tst ttd tto ttr tts ttt