ddd ddi ddo ddp dds ddt di- did dii dio dip dis dit dod doi doo dop dos dot dpd dpi dpo dpp dps dpt dsd dsi dso dsp dss dst dtd dti dto dtp dts dtt i-d idd idi ido idp ids idt iid iii iio iip iis iit io- iod ioi ioo iop ios iot ipd ipi ipo ipp ips ipt is- isd isi iso isp iss ist itd iti ito itp its itt o-i odd odi odo odp ods odt oid oii oio oip ois oit oo- ood ooi ooo oop oos oot op- opd opi opo opp ops opt os- osd osi oso osp oss ost ot- otd oti oto otp ots ott p-p pdd pdi pdo pdp pds pdt pid pii pio pip pis pit pod poi poo pop pos pot ppd ppi ppo ppp pps ppt ps- psd psi pso psp pss pst pt- ptd pti pto ptp pts ptt sdd sdi sdo sdp sds sdt sid sii sio sip sis sit sod soi soo sop sos sot spd spi spo spp sps spt ss- ssd ssi sso ssp sss sst std sti sto stp sts stt tdd tdi tdo tdp tds tdt tid tii tio tip tis tit to- tod toi too top tos tot tpd tpi tpo tpp tps tpt tsd tsi tso tsp tss tst ttd tti tto ttp tts ttt