ddd ddi ddp dds di- did dii dip dis div dpd dpi dpp dps dpv dsd dsi dsp dss dsv dvd dvi dvp dvs i-d i-v idd idi idp ids idv iid iii iip iis ipd ipi ipp ips ipv is- isd isi isp iss isv ivd ivi ivp ivs ivv p-p pdd pdi pdp pds pdv pid pii pip pis piv ppd ppi ppp pps ppv ps- psd psi psp pss psv pvd pvi pvp pvs pvv sdd sdi sdp sds sdv sid sii sip sis siv spd spi spp sps spv ss- ssd ssi ssp sss ssv svd svi svp svs svv vdd vdi vdp vds vdv vi- vid vii vip vis viv vpd vpi vpp vps vsd vsi vsp vss vsv vvi vvs vvv