-er a-a a-b a-i a-t aaa aab aae aai aao aap aar aat ab- aba abb abe abi abo abp abr abt aea aeb aee aei aeo aep aer aet ai- aia aib aie aii aio aip air ait aoa aob aoe aoi aoo aop aor aot ap- apa apb ape api apo app apr apt ar- ara arb are ari aro arp arr art at- ata atb ate ati ato atp atr att b-p baa bab bae bai bao bap bar bat bba bbb bbe bbi bbo bbp bbr bbt be- bea beb bee bei beo bep ber bet bi- bia bib bie bii bio bip bir bit boa bob boe boi boo bop bor bot bpa bpb bpe bpi bpo bpp bpr bpt bra brb bre bri bro brp brr brt bta btb bte bti bto btp btr btt eaa eab eae eai eao eap ear eat eba ebb ebe ebi ebo ebp ebr ebt eea eeb eee eeo eep eer eet eia eib eie eii eio eip eir eit eo- eoa eob eoe eoi eoo eop eor eot ep- epa epb epe epi epo epp epr ept era erb ere eri ero erp err ert eta etb ete eti eto etp etr ett ia- iaa iab iae iai iao iap iar iat iba ibb ibe ibi ibo ibp ibr ibt ie- iea iee iei iep ier iet iia iib iie iii iio iip iir iit io- ioa iob ioe ioi ioo iop ior iot ipa ipb ipe ipi ipo ipp ipr ipt ir- ira irb ire iri iro irp irr irt ita itb ite iti ito itp itt o-i oaa oab oae oai oao oap oar oat ob- oba obb obe obi obo obp obr obt oea oeb oee oei oeo oep oer oet oia oib oie oii oio oip oir oit oo- ooa oob ooi ooo oop oor oot op- opa opb ope opi opo opp opr opt or- ora orb ore ori oro orp orr ort ot- ota otb ote oti oto otp otr ott p-p paa pab pae pai pao pap par pat pba pbb pbe pbi pbo pbp pbr pbt pea peb pee pei peo pep per pet pia pib pie pii pio pip pir pit poa pob poe poi poo pop por pot ppa ppb ppe ppi ppo ppp ppr ppt pra prb pre pri pro prp prr prt pt- pta ptb pte pti pto ptp ptr ptt ra- raa rab rae rai rao rap rar rat rba rbb rbe rbi rbo rbp rbr rbt re- rea reb ree rei reo rep rer ret ria rib rie rii rio rip rir rit roa rob roe roi roo rop ror rot rpa rpb rpe rpi rpo rpp rpr rpt rra rrb rri rrp rrr rrt rta rtb rte rti rto rtp rtr rtt taa tab tae tai tao tap tar tat tba tbb tbe tbi tbo tbp tbr tbt te- tea teb tee tei teo tep ter tet tia tib tie tii tio tip tir tit to- toa tob toe toi too top tor tot tpa tpb tpe tpi tpo tpp tpr tpt tra trb tre tri tro trp trr trt tta ttb tte tti tto ttp ttr ttt