a-a a-b a-t aaa aab aad aao aap aas aat ab- aba abb abd abo abp abs abt ad- ada adb add ado adp ads adt aoa aob aod aoo aop aos aot ap- apa apb apd apo app aps apt as- asa asb asd aso asp ass ast at- ata atb atd ato atp ats att b-p baa bab bad bao bap bas bat bba bbb bbd bbo bbp bbs bbt bda bdb bdd bdo bdp bds bdt boa bob bod boo bop bos bot bpa bpb bpd bpo bpp bps bpt bsa bsb bsd bso bsp bss bst bta btb btd bto btp bts btt daa dab dad dao dap das dat dba dbb dbd dbo dbp dbs dbt dda ddb ddd ddo ddp dds ddt doa dob dod doo dop dos dot dpa dpb dpd dpo dpp dps dpt dsa dsb dsd dso dsp dss dst dta dtb dtd dto dtp dts dtt oaa oab oad oao oap oas oat ob- oba obb obd obo obp obs obt oda odb odd odo odp ods odt oo- ooa oob ood ooo oop oos oot op- opa opb opd opo opp ops opt os- osa osb osd oso osp oss ost ot- ota otb otd oto otp ots ott p-p paa pab pad pao pap pas pat pba pbb pbd pbo pbp pbs pbt pda pdb pdd pdo pdp pds pdt poa pob pod poo pop pos pot ppa ppb ppd ppo ppp pps ppt ps- psa psb psd pso psp pss pst pt- pta ptb ptd pto ptp pts ptt saa sab sad sao sap sas sat sba sbb sbd sbo sbp sbs sbt sda sdb sdd sdo sdp sds sdt soa sob sod soo sop sos sot spa spb spd spo spp sps spt ss- ssa ssb ssd sso ssp sss sst sta stb std sto stp sts stt taa tab tad tao tap tas tat tba tbb tbd tbo tbp tbs tbt tda tdb tdd tdo tdp tds tdt to- toa tob tod too top tos tot tpa tpb tpd tpo tpp tps tpt tsa tsb tsd tso tsp tss tst tta ttb ttd tto ttp tts ttt