a-a a-b a-i a-t aaa aab aai aao aap aar aat ab- aba abb abi abo abp abr abt ai- aia aib aii aio aip air ait aoa aob aoi aoo aop aor aot ap- apa apb api apo app apr apt ar- ara arb ari aro arp arr art at- ata atb ati ato atp atr att b-p baa bab bai bao bap bar bat bba bbb bbi bbo bbp bbr bbt bi- bia bib bii bio bip bir bit boa bob boi boo bop bor bot bpa bpb bpi bpo bpp bpr bpt bra brb bri bro brp brr brt bta btb bti bto btp btr btt ia- iaa iab iai iao iap iar iat iba ibb ibi ibo ibp ibr ibt iia iib iii iio iip iir iit io- ioa iob ioi ioo iop ior iot ipa ipb ipi ipo ipp ipr ipt ir- ira irb iri iro irp irr irt ita itb iti ito itp itt o-i oaa oab oai oao oap oar oat ob- oba obb obi obo obp obr obt oia oib oii oio oip oir oit oo- ooa oob ooi ooo oop oor oot op- opa opb opi opo opp opr opt or- ora orb ori oro orp orr ort ot- ota otb oti oto otp otr ott p-p paa pab pai pao pap par pat pba pbb pbi pbo pbp pbr pbt pia pib pii pio pip pir pit poa pob poi poo pop por pot ppa ppb ppi ppo ppp ppr ppt pra prb pri pro prp prr prt pt- pta ptb pti pto ptp ptr ptt ra- raa rab rai rao rap rar rat rba rbb rbi rbo rbp rbr rbt ria rib rii rio rip rir rit roa rob roi roo rop ror rot rpa rpb rpi rpo rpp rpr rpt rra rrb rri rrp rrr rrt rta rtb rti rto rtp rtr rtt taa tab tai tao tap tar tat tba tbb tbi tbo tbp tbr tbt tia tib tii tio tip tir tit to- toa tob toi too top tor tot tpa tpb tpi tpo tpp tpr tpt tra trb tri tro trp trr trt tta ttb tti tto ttp ttr ttt