a-a a-b a-i a-t aaa aab aai aao aap aar aas aat ab- aba abb abi abo abp abr abs abt ai- aia aib aii aio aip air ais ait aoa aob aoi aoo aop aor aos aot ap- apa apb api apo app apr aps apt ar- ara arb ari aro arp arr ars art as- asa asb asi aso asp asr ass ast at- ata atb ati ato atp atr ats att b-p baa bab bai bao bap bar bas bat bba bbb bbi bbo bbp bbr bbs bbt bi- bia bib bii bio bip bir bis bit boa bob boi boo bop bor bos bot bpa bpb bpi bpo bpp bpr bps bpt bra brb bri bro brp brr brs brt bsa bsb bsi bso bsp bsr bss bst bta btb bti bto btp btr bts btt ia- iaa iab iai iao iap iar ias iat iba ibb ibi ibo ibp ibr ibs ibt iia iib iii iio iip iir iis iit io- ioa iob ioi ioo iop ior ios iot ipa ipb ipi ipo ipp ipr ips ipt ir- ira irb iri iro irp irr irs irt is- isa isb isi iso isp isr iss ist ita itb iti ito itp its itt o-i oaa oab oai oao oap oar oas oat ob- oba obb obi obo obp obr obs obt oia oib oii oio oip oir ois oit oo- ooa oob ooi ooo oop oor oos oot op- opa opb opi opo opp opr ops opt or- ora orb ori oro orp orr ors ort os- osa osb osi oso osp osr oss ost ot- ota otb oti oto otp otr ots ott p-p paa pab pai pao pap par pas pat pba pbb pbi pbo pbp pbr pbs pbt pia pib pii pio pip pir pis pit poa pob poi poo pop por pos pot ppa ppb ppi ppo ppp ppr pps ppt pra prb pri pro prp prr prs prt ps- psa psb psi pso psp psr pss pst pt- pta ptb pti pto ptp ptr pts ptt ra- raa rab rai rao rap rar ras rat rba rbb rbi rbo rbp rbr rbs rbt ria rib rii rio rip rir ris rit roa rob roi roo rop ror ros rot rpa rpb rpi rpo rpp rpr rps rpt rra rrb rri rrp rrr rrs rrt rsa rsb rsi rso rsp rsr rss rst rta rtb rti rto rtp rtr rts rtt saa sab sai sao sap sar sas sat sba sbb sbi sbo sbp sbr sbs sbt sia sib sii sio sip sir sis sit soa sob soi soo sop sor sos sot spa spb spi spo spp spr sps spt sr- sra srb sri sro srp srr srs srt ss- ssa ssb ssi sso ssp ssr sss sst sta stb sti sto stp str sts stt taa tab tai tao tap tar tas tat tba tbb tbi tbo tbp tbr tbs tbt tia tib tii tio tip tir tis tit to- toa tob toi too top tor tos tot tpa tpb tpi tpo tpp tpr tps tpt tra trb tri tro trp trr trs trt tsa tsb tsi tso tsp tsr tss tst tta ttb tti tto ttp ttr tts ttt