a-a a-t aaa aaf aao aap aas aat af- afa aff afo afp afs aft aoa aof aoo aop aos aot ap- apa apf apo app aps apt as- asa asf aso asp ass ast at- ata atf ato atp ats att faa faf fao fap fas fat ffa fff ffo ffp ffs fft foa fof foo fop fos fot fpa fpo fpp fps fpt fsa fsf fso fsp fss fst fta ftf fto ftp fts ftt oaa oaf oao oap oas oat of- ofa off ofo ofp ofs oft oo- ooa oof ooo oop oos oot op- opa opf opo opp ops opt os- osa osf oso osp oss ost ot- ota otf oto otp ots ott p-p paa paf pao pap pas pat pfa pff pfo pfp pfs pft poa pof poo pop pos pot ppa ppf ppo ppp pps ppt ps- psa psf pso psp pss pst pt- pta ptf pto ptp pts ptt saa saf sao sap sas sat sfa sff sfo sfp sfs sft soa sof soo sop sos sot spa spf spo spp sps spt ss- ssa ssf sso ssp sss sst sta stf sto stp sts stt taa taf tao tap tas tat tfa tff tfo tfp tfs tft to- toa tof too top tos tot tpa tpf tpo tpp tps tpt tsa tsf tso tsp tss tst tta ttf tto ttp tts ttt