dddd ddps ddss ddts dntp dntt dpdt dpsd dpst dpts dsdp dsps dspt dssn dssp dsst dstn dsts dtdp dtss dttp ndnp ndnt ndpd ndps ndss nnnn nnss nntn nppd npss nptn nsds nsdt nsps nssp nsss nstd nstp nsts ntds ntnd ntpd ntss pdns pdpn pdsd pdss pnpp pntd ppds pppd pppn pppp ppps ppss pptn ppts pptt psdp psds pspp psps psst psts ptpd ptsd sdds sdps sdss snns snpp snsd spdp spdt spns sppd spps spsd spsp spss spst spts ssdd ssdp ssns ssps sspt ssss sstd sstp ssts stds stnd stnn stns stpd stpp stps stss sttd tdss tndd tnsp tnts tppd tppp tptp tspn tsps tspt tsst tsts ttss tttt