ddd ddr dds ddt drd drr drs drt drv dsd dsr dss dst dsv dtd dtr dts dtt dtv dvd dvr dvs dvt rdd rdr rds rdt rdv rrd rrr rrs rrt rsd rsr rss rst rsv rtd rtr rts rtt rtv rvd rvr rvs rvt rvv sdd sdr sds sdt sdv sr- srd srr srs srt srv ss- ssd ssr sss sst ssv std str sts stt stv svd svr svs svt svv tdd tdr tds tdt tdv trd trr trs trt trv tsd tsr tss tst tsv ttd ttr tts ttt ttv tvd tvr tvs tvt vdd vdr vds vdt vdv vrd vrr vrs vrt vsd vsr vss vst vsv vtr vts vtt vtv vvr vvs vvt vvv