a-a a-b a-t aaa aab aan aap aas aat ab- aba abb abn abp abs abt an- ana anb ann anp ans ant ap- apa apb apn app aps apt as- asa asb asn asp ass ast at- ata atb atn atp ats att b-p baa bab ban bap bas bat bba bbb bbn bbp bbs bbt bna bnb bnn bnp bns bnt bpa bpb bpn bpp bps bpt bsa bsb bsn bsp bss bst bta btb btn btp bts btt naa nab nan nap nas nat nba nbb nbn nbp nbs nbt nna nnb nnn nnp nns nnt npa npb npn npp nps npt nsa nsb nsn nsp nss nst nta ntb ntn ntp nts ntt p-p paa pab pan pap pas pat pba pbb pbn pbp pbs pbt pn- pna pnb pnn pnp pns pnt ppa ppb ppn ppp pps ppt ps- psa psb psn psp pss pst pt- pta ptb ptn ptp pts ptt saa sab san sap sas sat sba sbb sbn sbp sbs sbt sna snb snn snp sns snt spa spb spn spp sps spt ss- ssa ssb ssn ssp sss sst sta stb stn stp sts stt taa tab tan tap tas tat tba tbb tbn tbp tbs tbt tna tnb tnn tnp tns tnt tpa tpb tpn tpp tps tpt tsa tsb tsn tsp tss tst tta ttb ttn ttp tts ttt