ddd ddo ddp ddr dds ddt dod doo dop dor dos dot dpd dpo dpp dpr dps dpt drd dro drp drr drs drt dsd dso dsp dsr dss dst dtd dto dtp dtr dts dtt odd odo odp odr ods odt oo- ood ooo oop oor oos oot op- opd opo opp opr ops opt or- ord oro orp orr ors ort os- osd oso osp osr oss ost ot- otd oto otp otr ots ott p-p pdd pdo pdp pdr pds pdt pod poo pop por pos pot ppd ppo ppp ppr pps ppt prd pro prp prr prs prt ps- psd pso psp psr pss pst pt- ptd pto ptp ptr pts ptt rdd rdo rdp rdr rds rdt rod roo rop ror ros rot rpd rpo rpp rpr rps rpt rrd rrp rrr rrs rrt rsd rso rsp rsr rss rst rtd rto rtp rtr rts rtt sdd sdo sdp sdr sds sdt sod soo sop sor sos sot spd spo spp spr sps spt sr- srd sro srp srr srs srt ss- ssd sso ssp ssr sss sst std sto stp str sts stt tdd tdo tdp tdr tds tdt to- tod too top tor tos tot tpd tpo tpp tpr tps tpt trd tro trp trr trs trt tsd tso tsp tsr tss tst ttd tto ttp ttr tts ttt