ddd ddi ddp dds ddt di- did dii dip dis dit dpd dpi dpp dps dpt dsd dsi dsp dss dst dtd dti dtp dts dtt i-d idd idi idp ids idt iid iii iip iis iit ipd ipi ipp ips ipt is- isd isi isp iss ist itd iti itp its itt p-p pdd pdi pdp pds pdt pid pii pip pis pit ppd ppi ppp pps ppt ps- psd psi psp pss pst pt- ptd pti ptp pts ptt sdd sdi sdp sds sdt sid sii sip sis sit spd spi spp sps spt ss- ssd ssi ssp sss sst std sti stp sts stt tdd tdi tdp tds tdt tid tii tip tis tit tpd tpi tpp tps tpt tsd tsi tsp tss tst ttd tti ttp tts ttt