a-a a-t aaa aao aap aas aat aoa aoo aop aos aot ap- apa apo app aps apt as- asa aso asp ass ast at- ata ato atp ats att oaa oao oap oas oat oo- ooa ooo oop oos oot op- opa opo opp ops opt os- osa oso osp oss ost ot- ota oto otp ots ott p-p paa pao pap pas pat poa poo pop pos pot ppa ppo ppp pps ppt ps- psa pso psp pss pst pt- pta pto ptp pts ptt saa sao sap sas sat soa soo sop sos sot spa spo spp sps spt ss- ssa sso ssp sss sst sta sto stp sts stt taa tao tap tas tat to- toa too top tos tot tpa tpo tpp tps tpt tsa tso tsp tss tst tta tto ttp tts ttt