ddd ddo ddp ddr dds dod doo dop dor dos dpd dpo dpp dpr dps drd dro drp drr drs dsd dso dsp dsr dss odd odo odp odr ods oo- ood ooo oop oor oos op- opd opo opp opr ops or- ord oro orp orr ors os- osd oso osp osr oss p-p pdd pdo pdp pdr pds pod poo pop por pos ppd ppo ppp ppr pps prd pro prp prr prs ps- psd pso psp psr pss rdd rdo rdp rdr rds rod roo rop ror ros rpd rpo rpp rpr rps rrd rrp rrr rrs rsd rso rsp rsr rss sdd sdo sdp sdr sds sod soo sop sor sos spd spo spp spr sps sr- srd sro srp srr srs ss- ssd sso ssp ssr sss